a(n) = 4*n^2 - 3*n + 1.

Terms

a(0) =1a(1) =2a(2) =11a(3) =28a(4) =53a(5) =86a(6) =127a(7) =176a(8) =233a(9) =298a(10) =371a(11) =452a(12) =541a(13) =638a(14) =743a(15) =856a(16) =977a(17) =1106a(18) =1243a(19) =1388a(20) =1541a(21) =1702a(22) =1871a(23) =2048a(24) =2233a(25) =2426a(26) =2627a(27) =2836a(28) =3053a(29) =3278