a(n) = a(n-1) + 12*n for n > 1; a(1) = 1.

Terms

a(0) =1a(1) =25a(2) =61a(3) =109a(4) =169a(5) =241a(6) =325a(7) =421a(8) =529a(9) =649a(10) =781a(11) =925a(12) =1081a(13) =1249a(14) =1429a(15) =1621a(16) =1825a(17) =2041a(18) =2269a(19) =2509a(20) =2761a(21) =3025a(22) =3301a(23) =3589a(24) =3889a(25) =4201a(26) =4525a(27) =4861a(28) =5209a(29) =5569