Just a bad idea...

numberedArray.m

#import <Foundation/Foundation.h>

@interface NSMutableArray (badidea)
- (NSArray *) upto:(NSUInteger)n;
@end

@implementation NSMutableArray (badidea)
- (NSArray *) upto:(NSUInteger)n
{
    if (n==0) return self.reverseObjectEnumerator.allObjects;
    [self addObject:@(n)];
    return [self upto:(n-1)];
}
@end


int main(int argc, char *argv[]) {
    @autoreleasepool {
       NSMutableArray *array = [NSMutableArray array];
       NSLog(@"%@", [array upto:50]); 
    }
}