a(n) = (4n+1)^5.

Terms

a(0) =1a(1) =3125a(2) =59049a(3) =371293a(4) =1419857a(5) =4084101a(6) =9765625a(7) =20511149a(8) =39135393a(9) =69343957a(10) =115856201a(11) =184528125a(12) =282475249a(13) =418195493a(14) =601692057a(15) =844596301a(16) =1160290625a(17) =1564031349a(18) =2073071593a(19) =2706784157a(20) =3486784401a(21) =4437053125a(22) =5584059449a(23) =6956883693a(24) =8587340257a(25) =10510100501