Column 0 of triangle A117250.

A117251

Column 0 of triangle A117250.

Terms

    a(0) =1a(1) =1a(2) =-1a(3) =4a(4) =-40a(5) =896a(6) =-43008a(7) =4325376a(8) =-899678208a(9) =383862702080

External references