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A185092
Numbers k such that j^j == j^j^j (mod k) for every j.
0
1, 2, 3, 4, 6, 12
OFFSET
1,2
COMMENTS
Divisors of 12. For k <= 16, we may compute membership directly (see Mathematica code). For k > 16, we have j = 2 as a counterexample. - Eric M. Schmidt, Aug 03 2014
MATHEMATICA
h1[mod_] := Table[PowerMod[i, i, mod], {i, 1, mod + LCM[mod*CarmichaelLambda[mod]]}]; h2[mod_] := Table[PowerMod[i, i^i, mod], {i, 1, mod + LCM[mod*CarmichaelLambda[mod]]}]; Union[Table[If[h1[i] == h2[i], Print[i]; i], {i, 1000}]]
CROSSREFS
Sequence in context: A375169 A061941 A029505 * A218337 A335993 A018309
KEYWORD
nonn,fini,full
AUTHOR
STATUS
approved