Indices of centered heptagonal numbers (A069099) that are also octagonal numbers (A000567).
A254856
Indices of centered heptagonal numbers (A069099) that are also octagonal numbers (A000567).
Terms
- a(0) =1a(1) =2a(2) =15a(3) =40a(4) =377a(5) =1026a(6) =9775a(7) =26624a(8) =253761a(9) =691186a(10) =6587999a(11) =17944200a(12) =171034201a(13) =465858002a(14) =4440301215a(15) =12094363840a(16) =115276797377a(17) =313987601826
External references
- oeis: A254856