login
Values of n such that p(2n+1) mod 12 = 1, where p(j) denotes the j-th prime.
7

%I #14 Oct 28 2017 10:48:15

%S 10,12,14,18,26,29,32,60,63,72,73,75,79,84,91,93,94,95,98,101,105,110,

%T 115,118,125,128,131,135,136,137,139,143,147,150,159,165,168,169,170,

%U 173,177,180,184,187,195,200,203,205,207,212,215,217,218,221,222,224

%N Values of n such that p(2n+1) mod 12 = 1, where p(j) denotes the j-th prime.

%H G. C. Greubel, <a href="/A116612/b116612.txt">Table of n, a(n) for n = 1..5000</a>

%F A116612 = integer part of 1/2 * { odd terms in A160594 = A000720(A068228) }. - _M. F. Hasler_, May 22 2009

%e 29 is in the sequence because the 59th prime is 277 and 277 mod 12=1.

%p a:=proc(n) if ithprime(2*n+1) mod 12 = 1 then n else fi end: seq(a(n),n=0..250);

%t Select[Range[0, 2000], Mod[Prime[2*# + 1], 12] == 1 &] (* _G. C. Greubel_, Oct 27 2017 *)

%o (PARI) for(n=1,999, prime(2*n+1)%12==1 & print1(n",")) \\ _M. F. Hasler_, May 22 2009

%Y Cf. A116602, A116610, A116613-A116617, A160591-A160594. [_M. F. Hasler_, May 22 2009]

%K nonn

%O 1,1

%A _Roger L. Bagula_, Mar 29 2006

%E Edited by _N. J. A. Sloane_, Apr 05 2006