a(n) = (3*n+9)!!!/9!!!, related to A032031 ((3*n)!!! triple factorials).

A051609

a(n) = (3*n+9)!!!/9!!!, related to A032031 ((3*n)!!! triple factorials).

Terms

    a(0) =1a(1) =12a(2) =180a(3) =3240a(4) =68040a(5) =1632960a(6) =44089920a(7) =1322697600a(8) =43649020800

External references