One half of third column (k=2) of triangle A111999.

A112000

One half of third column (k=2) of triangle A111999.

Terms

    a(0) =-3a(1) =65a(2) =-1190a(3) =22050a(4) =-433125a(5) =9144135a(6) =-208107900a(7) =5099994900a(8) =-134219460375

External references