a(n) = n^3*(n^5 + 1)/2.

Terms

a(0) =0a(1) =1a(2) =132a(3) =3294a(4) =32800a(5) =195375a(6) =839916a(7) =2882572a(8) =8388864a(9) =21523725a(10) =50000500a(11) =107180106a(12) =214991712a(13) =407866459a(14) =737895900a(15) =1281447000a(16) =2147485696a(17) =3487881177a(18) =5509983204a(19) =8491784950a(20) =12800004000a(21) =18911434311a(22) =27437942092