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

A253674

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

Terms

    a(0) =1a(1) =10a(2) =40a(3) =931a(4) =3871a(5) =91180a(6) =379270a(7) =8934661a(8) =37164541a(9) =875505550a(10) =3641745700a(11) =85790609191a(12) =356853914011

External references