Number of n X n triangular matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to 2n.

A357141

Number of n X n triangular matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to 2n.

Terms

    a(0) =1a(1) =1a(2) =6a(3) =71a(4) =1433a(5) =44443a(6) =1968580a(7) =118159971a(8) =9240555677a(9) =913352224942

External references