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 A290543 Composite numbers n such that A290542(n) >= 2. 2
 28, 65, 66, 85, 91, 105, 117, 121, 124, 133, 145, 153, 154, 165, 185, 186, 190, 205, 217, 221, 231, 244, 246, 247, 259, 273, 276, 280, 286, 292, 301, 305, 310, 325, 341, 343, 344, 357, 364, 366, 369, 370, 377, 385, 396, 418, 425, 427, 429, 430, 435, 451 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Is a(n) ~ n * log n as n -> infinity? LINKS Table of n, a(n) for n=1..52. MATHEMATICA Select[Flatten@ Position[#, k_ /; k >= 2], CompositeQ] &@ Table[SelectFirst[Range[2, Sqrt@ n], PowerMod[#, n , n] == Mod[#, n] &], {n, 451}] (* Michael De Vlieger, Aug 09 2017 *) PROG (Magma) lst:=[]; for n in [4..451] do if not IsPrime(n) then r:=Floor(Sqrt(n)); for k in [2..r] do if Modexp(k, n, n) eq k then Append(~lst, n); break; end if; end for; end if; end for; lst; CROSSREFS Cf. A001567, A006935, A122780, A122781, A122782, A122783, A122784, A122785, A122786, A290542. Sequence in context: A043386 A044130 A044511 * A344044 A183230 A246911 Adjacent sequences: A290540 A290541 A290542 * A290544 A290545 A290546 KEYWORD nonn AUTHOR Arkadiusz Wesolowski, Aug 05 2017 STATUS approved

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Last modified August 12 19:26 EDT 2024. Contains 375113 sequences. (Running on oeis4.)