Twice 13-gonal numbers: a(n) = n*(11*n - 9).

Terms

a(0) =0a(1) =2a(2) =26a(3) =72a(4) =140a(5) =230a(6) =342a(7) =476a(8) =632a(9) =810a(10) =1010a(11) =1232a(12) =1476a(13) =1742a(14) =2030a(15) =2340a(16) =2672a(17) =3026a(18) =3402a(19) =3800a(20) =4220a(21) =4662a(22) =5126a(23) =5612a(24) =6120a(25) =6650a(26) =7202a(27) =7776a(28) =8372a(29) =8990