Indices of centered heptagonal numbers (A069099) which are also heptagonal numbers (A000566).

A133272

Indices of centered heptagonal numbers (A069099) which are also heptagonal numbers (A000566).

Terms

    a(0) =1a(1) =7a(2) =78a(3) =924a(4) =11005a(5) =131131a(6) =1562562a(7) =18619608a(8) =221872729a(9) =2643853135a(10) =31504364886a(11) =375408525492

External references