14-gonal (or tetradecagonal) numbers: a(n) = n*(6*n-5).

Terms

a(0) =0a(1) =1a(2) =14a(3) =39a(4) =76a(5) =125a(6) =186a(7) =259a(8) =344a(9) =441a(10) =550a(11) =671a(12) =804a(13) =949a(14) =1106a(15) =1275a(16) =1456a(17) =1649a(18) =1854a(19) =2071a(20) =2300a(21) =2541a(22) =2794a(23) =3059a(24) =3336a(25) =3625a(26) =3926a(27) =4239a(28) =4564a(29) =4901