cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A139233 Second differences of perfect numbers A000396, divided by 2.

Original entry on oeis.org

223, 3582, 16767288, 4261388256, 60146251776, 1152921370926219264, 1329227995784915870021503368556314624, 95780971304118050988940697472320075563727548890218496
Offset: 1

Views

Author

Omar E. Pol, Apr 19 2008

Keywords

Crossrefs

Programs

  • Mathematica
    Differences[PerfectNumber[Range[12]],2]/2 (* Paolo Xausa, Oct 20 2023 *)

Formula

a(n) = A139230(n)/2.

Extensions

a(5)-a(8) from Jinyuan Wang, Mar 04 2020