Number of lower triangles of an n X n integer array with all row and column sums zero and all row and column sums of squares <=18.

A195887

Number of lower triangles of an n X n integer array with all row and column sums zero and all row and column sums of squares <=18.

Terms

    a(0) =1a(1) =1a(2) =7a(3) =175a(4) =14831a(5) =4857647a(6) =5181491667

External references