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A128126
Numbers k such that 2^k == 18 (mod k).
9
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
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 k such that 2^k == 3 (mod k)), A033981, A051447, A033982, A051446, A033983, A128121, A128122, A128123, A128124, A128125.
Sequence in context: A230894 A291152 A145910 * A367646 A367578 A134647
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