a(n) = 28*n^2 + 1.

Terms

a(0) =1a(1) =29a(2) =113a(3) =253a(4) =449a(5) =701a(6) =1009a(7) =1373a(8) =1793a(9) =2269a(10) =2801a(11) =3389a(12) =4033a(13) =4733a(14) =5489a(15) =6301a(16) =7169a(17) =8093a(18) =9073a(19) =10109a(20) =11201a(21) =12349a(22) =13553a(23) =14813a(24) =16129a(25) =17501a(26) =18929a(27) =20413a(28) =21953a(29) =23549