Binomial coefficient C(5n,n-5).

Terms

a(0) =1a(1) =30a(2) =595a(3) =9880a(4) =148995a(5) =2118760a(6) =28989675a(7) =386206920a(8) =5047381560a(9) =65033528560a(10) =828931106355