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

Terms

a(0) =3125a(1) =248832a(2) =2476099a(3) =11881376a(4) =39135393a(5) =102400000a(6) =229345007a(7) =459165024a(8) =844596301a(9) =1453933568a(10) =2373046875a(11) =3707398432a(12) =5584059449a(13) =8153726976a(14) =11592740743a(15) =16105100000a(16) =21924480357a(17) =29316250624