#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

int a[301][45000];

#define MD 1000000007

main(){
	int n,k;
	scanf("%d%d",&n,&k);
	a[0][0]=1;
	for(int y=1;y<=n;++y){
		long t=1;
		a[y][0]=1;
		int xm2=y*(y-1)/2;
		int xm1=xm2/2;
		int x=1;
		for(;x<y;++x){
			a[y][x]=t=(t+a[y-1][x])%MD;
		}
		for(;x<=xm1;++x){
			a[y][x]=t=(t+a[y-1][x]-a[y-1][x-y])%MD;
		}
		for(;x<=xm2;++x){
			a[y][x]=a[y][xm2-x];
		}
	}
	long z=0;
	for(int x=0;x<=k;++x){
		z+=a[n][x];
	}
	printf("%d",(z%MD+MD)%MD);
}