a(n) = n*(7*n + 11)/2 + 1.

Terms

a(0) =1a(1) =10a(2) =26a(3) =49a(4) =79a(5) =116a(6) =160a(7) =211a(8) =269a(9) =334a(10) =406a(11) =485a(12) =571a(13) =664a(14) =764a(15) =871a(16) =985a(17) =1106a(18) =1234a(19) =1369a(20) =1511a(21) =1660a(22) =1816a(23) =1979a(24) =2149a(25) =2326a(26) =2510a(27) =2701a(28) =2899a(29) =3104