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 A128126 Numbers n such that 2^n == 18 (mod n). 8
 1, 2, 14, 35, 77, 98, 686, 1715, 5957, 18995, 26075, 43921, 49901, 52334, 86555, 102475, 221995, 250355, 1228283, 1493597, 4260059, 6469715, 10538675, 15374219, 19617187, 22731275, 53391779, 60432239, 68597795, 85672139, 175791077 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Joe Crump (joecr(AT)carolina.rr.com) Table of n, a(n) for n = 1..50 Joe K. Crump, 2^n mod n MATHEMATICA m = 18; Join[Select[Range[m], Divisible[2^# - m, #] &], Select[Range[m + 1, 10^6], PowerMod[2, #, #] == m &]] (* Robert Price, Oct 08 2018 *) PROG (PARI) isok(n) = Mod(2, n)^n == 18; \\ Michel Marcus, Oct 09 2018 (MAGMA) [1, 2, 14] cat [n: n in [1..10^8] | Modexp(2, n, n) eq 18]; // Vincenzo Librandi, Apr 05 2019 CROSSREFS Cf. A015910, A036236, A050259 = numbers n such that 2^n == 3 (mod n), A033981, A051447, A033982, A051446, A033983, A128121, A128122, A128123, A128124, A128125. Sequence in context: A230894 A291152 A145910 * A134647 A004117 A135706 Adjacent sequences:  A128123 A128124 A128125 * A128127 A128128 A128129 KEYWORD nonn AUTHOR Alexander Adamchuk, Feb 15 2007 EXTENSIONS More terms from Joe Crump (joecr(AT)carolina.rr.com), Mar 04 2007 1, 2 and 14 added by N. J. A. Sloane, Apr 23 2007 STATUS approved

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Last modified September 16 18:24 EDT 2019. Contains 327116 sequences. (Running on oeis4.)