a(1) = a(2) = 1; for n > 2, a(n) = (a(1), a(2), a(3), ...) dot (P(1), P(2), P(3), ...); P = A000129.

A159640

a(1) = a(2) = 1; for n > 2, a(n) = (a(1), a(2), a(3), ...) dot (P(1), P(2), P(3), ...); P = A000129.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =18a(4) =234a(5) =7020a(6) =498420a(7) =84731400a(8) =34655142600

External references