#include <bits/stdc++.h>

template <class T>
inline void read(T &res)
{
	char ch; bool flag = false; res = 0;
	while (ch = getchar(), !isdigit(ch) && ch != '-');
	ch == '-' ? flag = true : res = ch ^ 48;
	while (ch = getchar(), isdigit(ch))
		res = res * 10 + ch - 48; 
}

template <class T>
inline void put(T x)
{
	if (x > 9) put(x / 10);
	putchar(x % 10 + 48); 
}

const int N = 105;
const int N2 = 1e4 + 5; 
const int mod = 1e9 + 7;
const int inv2 = (mod + 1) >> 1;
int n, K, f[2][N2][N];

template <class T>
inline T Min(T x, T y) {return x < y ? x : y;}

inline void add(int &x, int y)
{
	x += y;
	x >= mod ? x -= mod : 0;
}

int main()
{
	read(n); read(K);
	f[0][0][0] = 1;
	for (int i = 1; i <= n; ++i)
	{
		int now = i & 1, lst = now ^ 1;
		for (int k = 0, km = Min(i * (i + 1), K); k <= km; ++k)
			for (int t = 0; t <= i; ++t)
				f[now][k][t] = 0;
		for (int k = 0, km = Min(i * (i - 1), K); k <= km; ++k)
			for (int t = 0; t < i; ++t)
				if (f[lst][k][t])
				{
					int cur = f[lst][k][t], a1 = (i - 1 - t), a2 = (i - 1 - t), b = n - t - a1 - a2;
					int &tmp1 = f[now][k + (i << 1)][t + 2];
					tmp1 = (1ll * a1 * a2 * cur + tmp1) % mod;
					int &tmp2 = f[now][k + i][t + 1];
					tmp2 = (1ll * cur * (a1 + a2) * b + tmp2) % mod;
					int &tmp3 = f[now][k][t];
					tmp3 = (1ll * b * (b - 1) * cur + tmp3) % mod;
					int &tmp4 = f[now][k + i][t + 1];
					tmp4 = (1ll * cur * b + tmp4) % mod; 
				}
	}
	put(f[n & 1][K][n]), putchar('\n');
}