Indices of pentagonal numbers (A000326) which are also centered pentagonal numbers (A005891).

A253654

Indices of pentagonal numbers (A000326) which are also centered pentagonal numbers (A005891).

Terms

    a(0) =1a(1) =6a(2) =46a(3) =361a(4) =2841a(5) =22366a(6) =176086a(7) =1386321a(8) =10914481a(9) =85929526a(10) =676521726a(11) =5326244281a(12) =41933432521a(13) =330141215886

External references