Pentagonal numbers (A000326) which are also centered heptagonal numbers (A069099).

A254654

Pentagonal numbers (A000326) which are also centered heptagonal numbers (A069099).

Terms

    a(0) =1a(1) =22a(2) =11572a(3) =265651a(4) =139997551a(5) =3213845272

External references