a(n) = 3*n^2 - 2.

Terms

a(0) =1a(1) =10a(2) =25a(3) =46a(4) =73a(5) =106a(6) =145a(7) =190a(8) =241a(9) =298a(10) =361a(11) =430a(12) =505a(13) =586a(14) =673a(15) =766a(16) =865a(17) =970a(18) =1081a(19) =1198a(20) =1321a(21) =1450a(22) =1585a(23) =1726a(24) =1873a(25) =2026a(26) =2185a(27) =2350a(28) =2521a(29) =2698