a(n) = (7*n + 4)^5.

Terms

a(0) =1024a(1) =161051a(2) =1889568a(3) =9765625a(4) =33554432a(5) =90224199a(6) =205962976a(7) =418195493a(8) =777600000a(9) =1350125107a(10) =2219006624a(11) =3486784401a(12) =5277319168a(13) =7737809375a(14) =11040808032a(15) =15386239549a(16) =21003416576a(17) =28153056843a(18) =37129300000a(19) =48261724457a(20) =61917364224a(21) =78502725751a(22) =98465804768a(23) =122298103125