309725

Appears in sequences

• Beach-Williams Pell numbers of type pqrs (p,q,r,s primes).at n=16A212080
• Number of 2Xn 0..1 arrays with every element equal to 0, 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=10A301842
• Triangular array read by rows: T(n,k) is the number of Boolean relation matrices such that all of the blocks of its Frobenius normal form are 0-blocks or 1-blocks and that have exactly k 1-blocks on the diagonal, n>=0, 0<=k<=n.at n=18A366141