login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A226216 Primes p such that (p-1)/ord(2,p) > (q-1)/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 (list; graph; refs; listen; history; text; internal format)
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 = (p-1)/ 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=(p-1)/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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 12 12:50 EST 2019. Contains 329958 sequences. (Running on oeis4.)