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

A253673

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

Terms

    a(0) =1a(1) =16a(2) =65a(3) =1520a(4) =6321a(5) =148896a(6) =619345a(7) =14590240a(8) =60689441a(9) =1429694576a(10) =5946945825a(11) =140095478160a(12) =582740001361

External references