login
Integers n such that 2^n == 17 (mod n).
9

%I #12 Oct 08 2018 18:14:23

%S 1,3,5,9,45,99,53559,1143357,2027985,36806085,1773607905,3314574181,

%T 1045463125509,1226640523999,3567404505159,28726885591099,

%U 39880799734039,87977068273719,106436400721299,339966033494859,999567363539883

%N Integers n such that 2^n == 17 (mod n).

%C Some larger terms: 576541379659648320485

%e 2^45 = 17 + 45*781874935307,

%e 2^99 = 17 + 99*6402275758728431320690420229.

%t m = 17; Join[Select[Range[m], Divisible[2^# - m, #] &],

%t Select[Range[m + 1, 10^6], PowerMod[2, #, #] == m &]] (* _Robert Price_, Oct 08 2018 *)

%Y Cf. A033981, A124965, A015911.

%K nonn

%O 1,2

%A _Zak Seidov_, Nov 14 2006

%E Terms 1, 3, 5, 9 prepended by _Max Alekseyev_, May 20 2011

%E a(11)-a(21) from _Max Alekseyev_, May 25 2012