Main diagonal of rectangular table A121428.

A121429

Main diagonal of rectangular table A121428.

Terms

    a(0) =1a(1) =2a(2) =18a(3) =250a(4) =4520a(5) =99351a(6) =2556806a(7) =75190410a(8) =2483617140a(9) =90955908010

External references