a(n) = (n+1)*(14*n^3+13*n^2+6*n+1).

Terms

a(0) =1a(1) =68a(2) =531a(3) =2056a(4) =5645a(5) =12636a(6) =24703a(7) =43856a(8) =72441a(9) =113140a(10) =168971a(11) =243288a(12) =339781a(13) =462476a(14) =615735a(15) =804256a(16) =1033073a(17) =1307556a(18) =1633411a(19) =2016680a(20) =2463741a(21) =2981308a(22) =3576431a(23) =4256496a(24) =5029225a(25) =5902676