a(n) = 5*n^5 - 3*n^3 - 2*n^2.

Terms

a(0) =0a(1) =0a(2) =128a(3) =1116a(4) =4896a(5) =15200a(6) =38160a(7) =82908a(8) =162176a(9) =292896a(10) =496800a(11) =801020a(12) =1238688a(13) =1849536a(14) =2680496a(15) =3786300a(16) =5230080a(17) =7083968a(18) =9429696a(19) =12359196a(20) =15975200a(21) =20391840a(22) =25735248a(23) =32144156a(24) =39770496a(25) =48780000a(26) =59352800a(27) =71684028a(28) =85984416a(29) =102480896