a(n) = 5^n*(n+4)!/n!.

A154128

a(n) = 5^n*(n+4)!/n!.

Terms

    a(0) =24a(1) =600a(2) =9000a(3) =105000a(4) =1050000a(5) =9450000a(6) =78750000a(7) =618750000a(8) =4640625000a(9) =33515625000a(10) =234609375000

External references