Column 2 of triangle A136220; also equals column 0 of U^3 = A136236 where U = A136228.

A136223

Column 2 of triangle A136220; also equals column 0 of U^3 = A136236 where U = A136228.

Terms

    a(0) =1a(1) =3a(2) =21a(3) =208a(4) =2637a(5) =40731a(6) =742620a(7) =15624420a(8) =372892266a(9) =9959561867a(10) =294465305959

External references