A145045 Primes p (A000043) such that 2^p-1 is prime (A000668) and congruent to 607 mod 6!

107, 86243, 756839, 25964951, 37156667

Offset

1,1

Comments

Mersenne numbers (with the exception of the first two) are congruent to 31, 127, 271, 607 mod 6!. This sequence is a subset of A000043.

Links

Table of n, a(n) for n=1..5.

Mathematica

p = {2, 3, 5, 7, 13, 17, 19, 31, 61, 89, 107, 127, 521, 607, 1279, 2203, 2281, 3217, 4253, 4423, 9689, 9941, 11213, 19937, 21701, 23209, 44497, 86243, 110503, 132049, 216091, 756839, 859433, 1257787, 1398269, 2976221, 3021377, 6972593, 13466917, 20996011, 24036583, 25964951, 30402457, 32582657, 37156667, 43112609}; a = {}; Do[If[Mod[2^p[[n]] - 1, 6! ] == 607, AppendTo[a, p[[n]]]], {n, 1, Length[p]}]; a (*Artur Jasinski*)

Crossrefs

Cf. A000043, A000668, A124477, A139484, A145038, A112633, A145041, A145042, A145044, A145045, A145046.

Sequence in context: A114356 A160488 A158476 * A113471 A057388 A192071

Adjacent sequences: A145042 A145043 A145044 * A145046 A145047 A145048

Keyword

nonn

Author

Artur Jasinski, Sep 30 2008

Extensions

Comment rewritten by Harvey P. Dale, Sep 02 2023

Status

approved