|
|
A068563
|
|
Numbers n such that 2^n == 4^n (mod n).
|
|
9
|
|
|
1, 2, 4, 6, 8, 12, 16, 18, 20, 24, 32, 36, 40, 42, 48, 54, 60, 64, 72, 80, 84, 96, 100, 108, 120, 126, 128, 136, 144, 156, 160, 162, 168, 180, 192, 200, 216, 220, 240, 252, 256, 272, 288, 294, 300, 312, 320, 324, 336, 342, 360, 378, 384, 400, 408, 420, 432, 440
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
If k is in the sequence then 2k is also in the sequence, but the converse is not true.
Also, integers n such that A007733(n) divides n. Also, integers n such that for every odd prime divisor p of n, A007733(p) = A002326((p-1)/2) divides n. Also, integers n such that A000265(n) divides 2^n-1. - Max Alekseyev, Aug 25 2013
|
|
LINKS
|
|
|
MATHEMATICA
|
Select[Range[500], PowerMod[2, #, # ] == PowerMod[4, #, # ] & ]
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
Comment and Mathematica program corrected by T. D. Noe, Oct 17 2008
|
|
STATUS
|
approved
|
|
|
|