This code print a Pascal triangle

pascal_triangle.go

package main

import (
	"fmt"
)

func main() {
	var N = 12
	for i := 0; i <= N; i++ {
		for j := 0; j <= i; j++ {
			if j == 0 {
				for k := 0; k <= N-i; k++ {
					fmt.Printf("   ")
				}
			} else {
				fmt.Printf("   ")
			}
			fmt.Printf("%3d", combi1(i, j))
		}
		fmt.Printf("\n")
	}
}

/*
 Pascal triangle formula 
    C(n,k) = n!/k!*(n-k)!
*/
func combi1(n, k int) int {
	switch k {
	case 0:
		return 1
	case 1:
		return n
	}
	if n == k {
		return 1
	}
	l := n - k
	if k > n {
		l = k - n
	}
	return factorial(n) / (factorial(k) * factorial(l))
}

func factorial(n int) int {
	switch {
	case n <= 0:
		return 0
	case n <= 2:
		return n
	}

	return n * factorial(n-1)
}