Triangular numbers of the form k^2 + 2.

Terms

a(0) =3a(1) =6a(2) =66a(3) =171a(4) =2211a(5) =5778a(6) =75078a(7) =196251a(8) =2550411a(9) =6666726a(10) =86638866a(11) =226472403a(12) =2943171003a(13) =7693394946a(14) =99981175206a(15) =261348955731