Truncated square numbers: 7*n^2 + 4*n + 1.

Terms

a(0) =1a(1) =12a(2) =37a(3) =76a(4) =129a(5) =196a(6) =277a(7) =372a(8) =481a(9) =604a(10) =741a(11) =892a(12) =1057a(13) =1236a(14) =1429a(15) =1636a(16) =1857a(17) =2092a(18) =2341a(19) =2604a(20) =2881a(21) =3172a(22) =3477a(23) =3796a(24) =4129a(25) =4476a(26) =4837a(27) =5212a(28) =5601a(29) =6004