Indices of centered triangular numbers (A005448) which are also heptagonal numbers (A000566).

A254675

Indices of centered triangular numbers (A005448) which are also heptagonal numbers (A000566).

Terms

    a(0) =1a(1) =13a(2) =44a(3) =776a(4) =2697a(5) =48069a(6) =167140a(7) =2979472a(8) =10359953a(9) =184679165a(10) =642149916a(11) =11447128728a(12) =39802934809a(13) =709537301941

External references