a(n) = n*(12*n^3 + 10*n^2 - 9*n - 7)/6.

Terms

a(0) =0a(1) =1a(2) =37a(3) =190a(4) =590a(5) =1415a(6) =2891a(7) =5292a(8) =8940a(9) =14205a(10) =21505a(11) =31306a(12) =44122a(13) =60515a(14) =81095a(15) =106520a(16) =137496a(17) =174777a(18) =219165a(19) =271510a(20) =332710a(21) =403711a(22) =485507a(23) =579140a(24) =685700a(25) =806325a(26) =942201a(27) =1094562a(28) =1264690a(29) =1453915