285D - Permutation Sum - CodeForces Solution

#include<bits/stdc++.h>
using namespace std;
const int mod=1e9+7;
long long a[20],b[20],n;
int main() 
{
    a[1]=1;
    a[3]=3;
    a[5]=15;
    a[7]=133;
    a[9]=2025;
    a[11]=37851;
    a[13]=1030367;
    a[15]=36362925;
    b[1]=1;
    for(int i=2;i<=16;i++) 
	{
        b[i]=(b[i-1]*i)%mod;
    }
    cin>>n;
    cout<<a[n]*b[n]%mod<<endl;
    return 0;
}