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

Terms

a(0) =0a(1) =0a(2) =0a(3) =48a(4) =264a(5) =840a(6) =2040a(7) =4200a(8) =7728a(9) =13104a(10) =20880a(11) =31680a(12) =46200a(13) =65208a(14) =89544a(15) =120120a(16) =157920a(17) =204000a(18) =259488a(19) =325584a(20) =403560a(21) =494760a(22) =600600a(23) =722568a(24) =862224a(25) =1021200a(26) =1201200a(27) =1404000a(28) =1631448a(29) =1885464