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.

A188130 Primes p such that 6p+1 divides the Mersenne number M(p)=A000225(p).

Original entry on oeis.org

5, 37, 73, 233, 397, 461, 557, 577, 601, 761, 1013, 1321, 1361, 1381, 1453, 1693, 1777, 1993, 2417, 2593, 2621, 2897, 3037, 3181, 3457, 3581, 3593, 4001, 4273, 4441, 4517, 4597, 4801, 4813, 4861, 4933, 5197, 5393, 5557, 5717, 5801, 6173, 6277, 6353, 6373, 6841, 6977, 7573, 7853, 7901, 8353, 8377, 9613, 10321, 10357
Offset: 1

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Author

M. F. Hasler, Mar 21 2011

Keywords

Comments

These primes are such that p=1 (mod 4) and 6p+1 is prime, but there are other primes with these properties (13, 17, ...) not in this sequence.
There are no primes p such that 4p+1 divides M(p), but those for which 2p+1 divides M(p) are the Lucasian primes A002515, and those for which 10p+1 divides M(p) are listed in A188133.

Crossrefs

Primes in A038844.

Programs

  • Mathematica
    Select[Range[10^4], PrimeQ[#] && PowerMod[2, #, 6# + 1] == 1 &] (* Amiram Eldar, Nov 13 2019 *)
  • PARI
    forprime(p=1,1e5,Mod(2,p*6+1)^p-1||print1(p", "))