A245583 Wieferich prime candidates: primes of the form A242139(n)+1 also having the form {m*(2^rs - 1)/(2^r - 1)}+1.

293, 439, 547, 1093, 1171, 2341, 3511

Offset

1,1

Comments

292 = 100100100, 438 = 110110110, 546 = 001000100010, 1092 = 010001000100, 1170 = 010010010010, 2340 = 100100100100, 3510 = 110110110110.

According to Dobson, all primes where m is of the form 2*(4^(r/2)-1)/3 cannot be Wieferich primes.

Triples (m, r, s) producing the terms through the formula in definition are (4, 3, 3), (6, 3, 3), (2, 4, 3), (4, 4, 3), (2, 3, 4), (4, 3, 4), (6, 3, 4).

Links

Table of n, a(n) for n=1..7.

S. Agou, Irréductibilité des polynômes f(X^p^r-aX) sur un corps fini F_p^s, J. reine angew. Mat. 292 (1977), 191-195.

J. B. Dobson, A note on the two known Wieferich primes (Archive of the site from August 28 2011)

Crossrefs

Cf. A001220, A242139.

Sequence in context: A155140 A248210 A142284 * A252409 A251682 A251675

Adjacent sequences: A245580 A245581 A245582 * A245584 A245585 A245586

Keyword

nonn,more

Author

Felix Fröhlich, Jul 26 2014

Status

approved