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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A306909 Primes p such that Omega(p + 1)^(p - 1) == 1 (mod p^2), where Omega is A001222.

Original entry on oeis.org

2, 11, 1093, 3511, 20771, 534851, 1006003, 3152573
Offset: 1

Views

Author

Felix Fröhlich, Mar 16 2019

Keywords

Comments

a(9) > 807795277 if it exists.
a(9) > 3.5*10^12 if it exists. - Giovanni Resta, Apr 09 2019

Examples

			A001222(20772) = 5 and 5^(20771-1) == 1 (mod 20771^2), so 20771 is a term of the sequence.

Crossrefs

Cf. A001220, A001222, A260377, A267487.

Programs

  • Mathematica
    Select[Prime@ Range@ 230000, PowerMod[ PrimeOmega[# + 1], #-1, #^2] == 1 &] (* Giovanni Resta, Apr 09 2019 *)
  • PARI
    forprime(p=1, , if(Mod(bigomega(p+1), p^2)^(p-1)==1, print1(p, ", ")))
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Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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