Indices of heptagonal numbers (A000566) that are also centered hexagonal numbers (A003215).

A254964

Indices of heptagonal numbers (A000566) that are also centered hexagonal numbers (A003215).

Terms

    a(0) =1a(1) =2a(2) =14a(3) =37a(4) =301a(5) =806a(6) =6602a(7) =17689a(8) =144937a(9) =388346a(10) =3182006a(11) =8525917a(12) =69859189a(13) =187181822a(14) =1533720146a(15) =4109474161a(16) =33671984017a(17) =90221249714a(18) =739249928222

External references