

A226216


Primes p such that (p1)/ord(2,p) > (q1)/ord(2,q) for odd primes q < p.


0



3, 7, 31, 73, 127, 601, 683, 1103, 1801, 2731, 5419, 8191, 43691, 61681, 65537, 121369, 122921, 131071, 178481, 262657, 524287, 2099863, 2796203, 6700417, 10567201, 13264529, 20394401, 48544121, 97685839, 112901153, 160465489, 164511353, 420778751, 536903681, 616318177
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OFFSET

1,1


COMMENTS

Essentially records in A001917. Sequence is infinite.
The Mersenne primes (A000668) are a subset.  Jeppe Stig Nielsen, Aug 30 2015


LINKS

Table of n, a(n) for n=1..35.


MATHEMATICA

r=0; p=3; L={}; While[Length@L < 20, v = (p1)/ MultiplicativeOrder[2, p]; If[v > r, r = v; AppendTo[L, p]]; p = NextPrime@ p]; L (* Giovanni Resta, Aug 31 2015 *)


PROG

(PARI) r=0; forprime(p=3, 1e9, t=(p1)/znorder(Mod(2, p)); if(t>r, r=t; print1(p", ")))


CROSSREFS

Cf. A001917.
Sequence in context: A091383 A166501 A261862 * A244114 A072881 A257924
Adjacent sequences: A226213 A226214 A226215 * A226217 A226218 A226219


KEYWORD

nonn


AUTHOR

Charles R Greathouse IV, May 31 2013


STATUS

approved



