C :

#include<stdio.h>
int main()
{
	int n;
	while((scanf("%d",&n))!=EOF)
	{
		if(n==0)
			break;
		int a[16]={1,0,0,2,10,4,40,92,352,724,2680,14200,73712,365596,2279184,14772512};
		printf("%d\n",a[n-1]);
	}
	return 0;
}

C++ :

#include<iostream>
#include<algorithm>
#include<cstring>
#include<ctime>
#include<cmath>
#include<string>
#include<cstdio>
using namespace std;

const int N = 16;

int c[N], a[2*N], b[2*N], m[N][N], ans[N+1], n, res;

void dfs(int r)
{
    if(r == n)
    {
        ++res; return;
    }
    for(int i = 0; i < n; ++i)
    {
        if(c[i] || a[r+i] || b[i-r+n-1] || m[r][i]) continue;
        c[i] = a[i+r] = b[i-r+n-1] = m[r][i] = 1;
        dfs(r+1);
        c[i] = a[i+r] = b[i-r+n-1] = m[r][i] = 0;
    }
}

int main()
{
    for(int i = 1; i < 16; ++i)
    {
        res = 0; n = i;
        memset(m, 0, sizeof(m));
        memset(a, 0, sizeof(a));
        memset(b, 0, sizeof(b));
        memset(c, 0, sizeof(c));
        dfs(0);
        ans[i] = res;
    }
    while(scanf("%d", &n),n)
    {
        printf("%d\n", ans[n]);
    }
    return 0;
}