a(n) = binomial coefficient C(n,47).

Terms

a(0) =1a(1) =48a(2) =1176a(3) =19600a(4) =249900a(5) =2598960a(6) =22957480a(7) =177100560a(8) =1217566350a(9) =7575968400a(10) =43183019880a(11) =227692286640