a(n) = 3*n^2 - 7*n + 6.

Terms

a(0) =6a(1) =2a(2) =4a(3) =12a(4) =26a(5) =46a(6) =72a(7) =104a(8) =142a(9) =186a(10) =236a(11) =292a(12) =354a(13) =422a(14) =496a(15) =576a(16) =662a(17) =754a(18) =852a(19) =956a(20) =1066a(21) =1182a(22) =1304a(23) =1432a(24) =1566a(25) =1706a(26) =1852a(27) =2004a(28) =2162a(29) =2326