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A069049 Numbers k such that 2^k mod k = 2^phi(k) mod phi(k). 0
1, 2, 4, 8, 14, 16, 22, 26, 32, 44, 46, 52, 62, 64, 92, 94, 108, 112, 118, 124, 128, 154, 164, 166, 188, 214, 222, 234, 236, 244, 252, 256, 258, 264, 288, 332, 334, 336, 358, 390, 412, 428, 438, 454, 456, 504, 512, 526, 534, 546, 576, 582, 630, 664, 668, 672 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Numbers k such that A015910(k) = A015910(A000010(k)). - Michel Marcus, Feb 11 2021

LINKS

Table of n, a(n) for n=1..56.

MATHEMATICA

Select[Range[1000], PowerMod[2, #, #] == PowerMod[2, (e = EulerPhi[#]), e] &] (* Amiram Eldar, Feb 11 2021 *)

PROG

(PARI) f(n) = lift(Mod(2, n)^n); \\ A015910

isok(k) = f(k) == f(eulerphi(k)); \\ Michel Marcus, Feb 11 2021

CROSSREFS

Cf. A000010, A015910.

Sequence in context: A121982 A143423 A253142 * A124853 A188629 A084621

Adjacent sequences:  A069046 A069047 A069048 * A069050 A069051 A069052

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Apr 03 2002

STATUS

approved

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Last modified September 20 22:20 EDT 2021. Contains 347596 sequences. (Running on oeis4.)