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 A130433 Even pseudoprimes to base 3. 15
 286, 24046, 232726, 1304446, 1707266, 2232026, 3197806, 3922126, 4446982, 5603326, 5886166, 10123366, 10169926, 12304774, 13658086, 45133726, 47766286, 52249654, 62656126, 75421126, 76254046, 91459126, 91612246, 96956926, 108571606, 139868326, 151513846 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The first 27 terms (halved) are given in Table 1 by Paszkiewicz and Rotkiewicz. - R. J. Mathar, Aug 22 2012 LINKS Jeppe Stig Nielsen, Table of n, a(n) for n = 1..68 A. Paszkiewicz and A. Rotkiewicz, On a Problem of H. J. A. Duprac, Tatra Mt. Math. Publ. 32 (2005) 15-32, MR2206908. Eric Weisstein's World of Mathematics, Fermat Pseudoprime. MATHEMATICA Do[ f=PowerMod[ 3, 2n-1, 2n ]; If[ f==1, Print[ 2n ] ], {n, 2, 7000000} ] PROG (PARI) forstep(n=4, 10^10, 2, Mod(3, n)^(n-1)==1 && print1(n, ", ")) \\ Jeppe Stig Nielsen, Apr 25 2018 CROSSREFS Even terms of A005935. Terms of A122780 that are congruent to 2 or 4 modulo 6. Cf. A006935, A090082, A090083, A090084, A090085. Cf. A130434, A130435, A130436, A130437, A130438, A130439, A130440, A130441, A130442, A130443. Sequence in context: A117994 A221431 A306144 * A140926 A295447 A203049 Adjacent sequences:  A130430 A130431 A130432 * A130434 A130435 A130436 KEYWORD nonn AUTHOR Alexander Adamchuk, May 26 2007, Jun 17 2007 EXTENSIONS More terms from Alexander Adamchuk, Jun 17 2007 a(25)-a(27) from Jeppe Stig Nielsen, Apr 25 2018 STATUS approved

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Last modified August 10 04:38 EDT 2020. Contains 336368 sequences. (Running on oeis4.)