Number of lower triangles of an n X n -7..7 array with all row and column sums zero.

A195521

Number of lower triangles of an n X n -7..7 array with all row and column sums zero.

Terms

    a(0) =1a(1) =1a(2) =15a(3) =1695a(4) =2563933a(5) =46387885537

External references