Calculating Nested Values

#include <stdio.h>
float p(float a, float b)
{
  return((b<100.0)?a+(b*b/p(a+2.0, b+1.0)):b*b);
}
int main()
{
  printf("%.7f\n", 4.0/p(1.0, 1.0));
  return(0);
}