Centered triangular numbers (A005448) which are also centered octagonal numbers (A016754).

A253675

Centered triangular numbers (A005448) which are also centered octagonal numbers (A016754).

Terms

    a(0) =1a(1) =361a(2) =6241a(3) =3463321a(4) =59923081a(5) =33254804881a(6) =575381414521

External references