a(n) = (10*n + 5)^5.

Terms

a(0) =3125a(1) =759375a(2) =9765625a(3) =52521875a(4) =184528125a(5) =503284375a(6) =1160290625a(7) =2373046875a(8) =4437053125a(9) =7737809375a(10) =12762815625a(11) =20113571875a(12) =30517578125a(13) =44840334375a(14) =64097340625a(15) =89466096875a(16) =122298103125a(17) =164130859375a(18) =216699865625a(19) =281950621875a(20) =362050628125a(21) =459401384375