a(n) = n^2 + n + 4.

Terms

a(0) =4a(1) =6a(2) =10a(3) =16a(4) =24a(5) =34a(6) =46a(7) =60a(8) =76a(9) =94a(10) =114a(11) =136a(12) =160a(13) =186a(14) =214a(15) =244a(16) =276a(17) =310a(18) =346a(19) =384a(20) =424a(21) =466a(22) =510a(23) =556a(24) =604a(25) =654a(26) =706a(27) =760a(28) =816a(29) =874