Indices of hexagonal numbers (A000384) that are also centered pentagonal numbers (A005891).

A254962

Indices of hexagonal numbers (A000384) that are also centered pentagonal numbers (A005891).

Terms

    a(0) =1a(1) =2a(2) =12a(3) =31a(4) =211a(5) =552a(6) =3782a(7) =9901a(8) =67861a(9) =177662a(10) =1217712a(11) =3188011a(12) =21850951a(13) =57206532a(14) =392099402a(15) =1026529561a(16) =7035938281a(17) =18420325562a(18) =126254789652a(19) =330539330551

External references