A130433 Even pseudoprimes to base 3.

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

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

Amiram Eldar, Table of n, a(n) for n = 1..215 (terms below 10^12, calculated from the b-file at A005935; terms 1..68 from Jeppe Stig Nielsen)

Adam Paszkiewicz and Andrzej 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.

Index entries for sequences related to pseudoprimes.

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