a(n) = n^6 + n.

Terms

a(0) =0a(1) =2a(2) =66a(3) =732a(4) =4100a(5) =15630a(6) =46662a(7) =117656a(8) =262152a(9) =531450a(10) =1000010a(11) =1771572a(12) =2985996a(13) =4826822a(14) =7529550a(15) =11390640a(16) =16777232a(17) =24137586a(18) =34012242a(19) =47045900a(20) =64000020a(21) =85766142a(22) =113379926a(23) =148035912a(24) =191103000a(25) =244140650a(26) =308915802