n e - ----------- 0 1 1 2 2 2.5 3 2.666666667 4 2.708333333
#include <stdio.h> double fun ( int i ) { double re = 2.5, to = 6; int n; for ( n = 3; n <= i; n++ ) { re += 1 / to; to *= ( n + 1 ); } return re; } int main() { int i; printf ( "n e\n" ); printf ( "- -----------\n" ); printf ( "0 1\n1 2\n2 2.5\n" ); for ( i = 3; i <= 9; i++ ) printf ( "%d %.9lf\n", i, fun ( i ) ); return 0; }
原文:http://blog.csdn.net/acm_baihuzi/article/details/41677307