G.f.: 1/((1-x)(1-4x)(1-10x)(1-12x)).

A021994

G.f.: 1/((1-x)(1-4x)(1-10x)(1-12x)).

Terms

    a(0) =1a(1) =27a(2) =495a(3) =7735a(4) =111111a(5) =1517607a(6) =20059495a(7) =259217895a(8) =3295741671a(9) =41400518887a(10) =515323813095

External references