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

Terms

a(0) =1024a(1) =59049a(2) =537824a(3) =2476099a(4) =7962624a(5) =20511149a(6) =45435424a(7) =90224199a(8) =164916224a(9) =282475249a(10) =459165024a(11) =714924299a(12) =1073741824a(13) =1564031349a(14) =2219006624a(15) =3077056399a(16) =4182119424a(17) =5584059449a(18) =7339040224a(19) =9509900499a(20) =12166529024a(21) =15386239549a(22) =19254145824a(23) =23863536599a(24) =29316250624a(25) =35723051649