This was a little program I quickly set up to get the idea how much experience would be required to gain a level. On 1 you need 10 points to become level 2, that's how you should read it.

Exp.c

#include <stdio.h>
#include <math.h>

const char DName[3][10] = {"Easy","Casual","Hard"};

double mul[3] = {0.125,0.25,0.50};

int exppnt[3] = {10,10,10};
//                  12345679
const int expmax = 100000000;

int main(void) {
	int lv=1;
	unsigned char notallmax=1;
	printf("%9s%9s%9s%9s\n","Level",DName[0],DName[1],DName[2]);	
	do{
		printf("%9d",lv++);
		for(int i=0;i<3;++i) {
			if (exppnt[i]<expmax) {
				printf("%9d",exppnt[i]);
				exppnt[i] += ((int)floor(exppnt[i]*mul[i]));				
			} else {
				printf("\x1b[31m%9s\x1b[0m","MAX!");
			}
		}
		printf("\n");
		notallmax=exppnt[0]<expmax || exppnt[1]<expmax || exppnt[2]<expmax;
	} while(notallmax);
}

Output.txt

    Level     Easy   Casual     Hard                          
        1       10       10       10                          
        2       11       12       15                          
        3       12       15       22                          
        4       13       18       33                          
        5       14       22       49                          
        6       15       27       73                          
        7       16       33      109                          
        8       18       41      163                          
        9       20       51      244                          
       10       22       63      366                          
       11       24       78      549                          
       12       27       97      823                          
       13       30      121     1234                          
       14       33      151     1851                          
       15       37      188     2776                          
       16       41      235     4164                          
       17       46      293     6246                          
       18       51      366     9369                          
       19       57      457    14053                          
       20       64      571    21079                          
       21       72      713    31618                          
       22       81      891    47427                          
       23       91     1113    71140                          
       24      102     1391   106710                          
       25      114     1738   160065                          
       26      128     2172   240097                          
       27      144     2715   360145                          
       28      162     3393   540217                          
       29      182     4241   810325                          
       30      204     5301  1215487                          
       31      229     6626  1823230                          
       32      257     8282  2734845                          
       33      289    10352  4102267                          
       34      325    12940  6153400                          
       35      365    16175  9230100                          
       36      410    20218 13845150                          
       37      461    25272 20767725                          
       38      518    31590 31151587                          
       39      582    39487 46727380                          
       40      654    49358 70091070                          
       41      735    61697     MAX!                          
       42      826    77121     MAX!                          
       43      929    96401     MAX!                          
       44     1045   120501     MAX!                          
       45     1175   150626     MAX!                          
       46     1321   188282     MAX!                          
       47     1486   235352     MAX!                          
       48     1671   294190     MAX!                          
       49     1879   367737     MAX!                          
       50     2113   459671     MAX!                          
       51     2377   574588     MAX!                          
       52     2674   718235     MAX!                          
       53     3008   897793     MAX!                          
       54     3384  1122241     MAX!                          
       55     3807  1402801     MAX!                          
       56     4282  1753501     MAX!                          
       57     4817  2191876     MAX!                          
       58     5419  2739845     MAX!                          
       59     6096  3424806     MAX!                          
       60     6858  4281007     MAX!                          
       61     7715  5351258     MAX!                          
       62     8679  6689072     MAX!                          
       63     9763  8361340     MAX!                          
       64    10983 10451675     MAX!                          
       65    12355 13064593     MAX!                          
       66    13899 16330741     MAX!                          
       67    15636 20413426     MAX!                          
       68    17590 25516782     MAX!                          
       69    19788 31895977     MAX!                          
       70    22261 39869971     MAX!                          
       71    25043 49837463     MAX!                          
       72    28173 62296828     MAX!                          
       73    31694 77871035     MAX!                          
       74    35655 97338793     MAX!                          
       75    40111     MAX!     MAX!                          
       76    45124     MAX!     MAX!                          
       77    50764     MAX!     MAX!                          
       78    57109     MAX!     MAX!                          
       79    64247     MAX!     MAX!                          
       80    72277     MAX!     MAX!                          
       81    81311     MAX!     MAX!                          
       82    91474     MAX!     MAX!                          
       83   102908     MAX!     MAX!                          
       84   115771     MAX!     MAX!                          
       85   130242     MAX!     MAX!                          
       86   146522     MAX!     MAX!                          
       87   164837     MAX!     MAX!                          
       88   185441     MAX!     MAX!                          
       89   208621     MAX!     MAX!                          
       90   234698     MAX!     MAX!                          
       91   264035     MAX!     MAX!                          
       92   297039     MAX!     MAX!                          
       93   334168     MAX!     MAX!                          
       94   375939     MAX!     MAX!                          
       95   422931     MAX!     MAX!                          
       96   475797     MAX!     MAX!                          
       97   535271     MAX!     MAX!                          
       98   602179     MAX!     MAX!                          
       99   677451     MAX!     MAX!                          
      100   762132     MAX!     MAX!                          
      101   857398     MAX!     MAX!                          
      102   964572     MAX!     MAX!                          
      103  1085143     MAX!     MAX!                          
      104  1220785     MAX!     MAX!                          
      105  1373383     MAX!     MAX!                          
      106  1545055     MAX!     MAX!                          
      107  1738186     MAX!     MAX!                          
      108  1955459     MAX!     MAX!                          
      109  2199891     MAX!     MAX!                          
      110  2474877     MAX!     MAX!                          
      111  2784236     MAX!     MAX!                          
      112  3132265     MAX!     MAX!                          
      113  3523798     MAX!     MAX!                          
      114  3964272     MAX!     MAX!                          
      115  4459806     MAX!     MAX!                          
      116  5017281     MAX!     MAX!                          
      117  5644441     MAX!     MAX!                          
      118  6349996     MAX!     MAX!                          
      119  7143745     MAX!     MAX!                          
      120  8036713     MAX!     MAX!                          
      121  9041302     MAX!     MAX!                          
      122 10171464     MAX!     MAX!                          
      123 11442897     MAX!     MAX!                          
      124 12873259     MAX!     MAX!                          
      125 14482416     MAX!     MAX!                          
      126 16292718     MAX!     MAX!                          
      127 18329307     MAX!     MAX!                          
      128 20620470     MAX!     MAX!                          
      129 23198028     MAX!     MAX!                          
      130 26097781     MAX!     MAX!                          
      131 29360003     MAX!     MAX!                          
      132 33030003     MAX!     MAX!                          
      133 37158753     MAX!     MAX!                          
      134 41803597     MAX!     MAX!                          
      135 47029046     MAX!     MAX!                          
      136 52907676     MAX!     MAX!                          
      137 59521135     MAX!     MAX!                          
      138 66961276     MAX!     MAX!                          
      139 75331435     MAX!     MAX!                          
      140 84747864     MAX!     MAX!                          
      141 95341347     MAX!     MAX!