Number of lower triangles of an n X n -2..2 array with all row and column sums zero.

A195516

Number of lower triangles of an n X n -2..2 array with all row and column sums zero.

Terms

    a(0) =1a(1) =1a(2) =5a(3) =65a(4) =3753a(5) =860017a(6) =839301197

External references