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.

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A323705 Odd primes p such that ((p+1)/2)^(p-1) == 1 (mod p^2).

Original entry on oeis.org

1897121, 52368101, 126233057
Offset: 1

Views

Author

Felix Fröhlich, Jan 24 2019

Keywords

Comments

The corresponding sequence when (p+1) in the congruence is replaced with (p-1) seems to be A125854.
a(4) > 4262937421 if it exists.

Crossrefs

Programs

  • Mathematica
    Select[Prime[Range[718*10^4]],PowerMod[(#+1)/2,#-1,#^2]==1&] (* Harvey P. Dale, May 14 2021 *)
  • PARI
    forprime(p=3, , my(x=(p+1)/2); if(Mod(x, p^2)^(p-1)==1, print1(p, ", ")))
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