Binomial coefficient C(n,26).

Terms

a(0) =1a(1) =27a(2) =378a(3) =3654a(4) =27405a(5) =169911a(6) =906192a(7) =4272048a(8) =18156204a(9) =70607460a(10) =254186856a(11) =854992152a(12) =2707475148a(13) =8122425444a(14) =23206929840a(15) =63432274896a(16) =166509721602a(17) =421171648758