156870
domain: N
Appears in sequences
- Numbers k such that both the sum of the semiprime divisors of k and the sum of the prime divisors of k are squares.at n=20A227478
- Triangle T(n, k) = the number of point-labeled graphs with n points and k edges, no points isolated, no edges isolated. By rows, 0 <= n, ceiling(2*n/3) <= k <= binomial(n, 2).at n=29A276640
- Regular triangle T(n,k) = binomial(2*n-2*k,n-k)*((n+1)/k)*Sum_{k=0..floor((k-1)/2)} (-1)^k*binomial(2*k,k)*binomial(n+3*k-2*k,k-2*k-1), read by rows.at n=31A306625