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A126043 Exponents p of the Mersenne primes 2^p - 1 (see A000043) read mod 3. 18
2, 0, 2, 1, 1, 2, 1, 1, 1, 2, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 1, 1, 2, 1, 1, 1, 2, 2, 1, 2, 2, 2, 2, 1, 1, 1, 2, 1, 2, 2, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..47.

FORMULA

a(n) = A010872(A000043(n)). - Michel Marcus, Aug 12 2014

MATHEMATICA

Array[Mod[MersennePrimeExponent@ #, 3] &, 45] (* Michael De Vlieger, Apr 07 2018 *)

PROG

(PARI) forprime(p=1, 1e3, if(isprime(2^p-1), print1(p%3, ", "))) \\ Felix Fröhlich, Aug 12 2014

CROSSREFS

Cf. A010872 (n mod 3), A126044-A126059.

Sequence in context: A104450 A281460 A035226 * A306659 A191225 A223893

Adjacent sequences:  A126040 A126041 A126042 * A126044 A126045 A126046

KEYWORD

nonn

AUTHOR

Artur Jasinski, Dec 17 2006

EXTENSIONS

a(45)-a(47) from Ivan Panchenko, Apr 08 2018

STATUS

approved

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Last modified July 11 20:03 EDT 2020. Contains 335652 sequences. (Running on oeis4.)