Number of pandigital numbers <= 10^n.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =3265920a(10) =182891520a(11) =5751285120a(12) =134183589120