a(n) = 36*n^2 + 6.

Terms

a(0) =42a(1) =150a(2) =330a(3) =582a(4) =906a(5) =1302a(6) =1770a(7) =2310a(8) =2922a(9) =3606a(10) =4362a(11) =5190a(12) =6090a(13) =7062a(14) =8106a(15) =9222a(16) =10410a(17) =11670a(18) =13002a(19) =14406a(20) =15882a(21) =17430a(22) =19050a(23) =20742a(24) =22506a(25) =24342a(26) =26250a(27) =28230a(28) =30282a(29) =32406