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

Terms

a(0) =0a(1) =2a(2) =15a(3) =60a(4) =170a(5) =390a(6) =777a(7) =1400a(8) =2340a(9) =3690a(10) =5555a(11) =8052a(12) =11310a(13) =15470a(14) =20685a(15) =27120a(16) =34952a(17) =44370a(18) =55575a(19) =68780a(20) =84210a(21) =102102a(22) =122705a(23) =146280a(24) =173100a(25) =203450a(26) =237627a(27) =275940a(28) =318710a(29) =366270