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A134671 Primes of the form 2m*691 - 1. 3
1381, 5527, 8291, 12437, 22111, 29021, 30403, 34549, 37313, 42841, 51133, 53897, 58043, 62189, 70481, 92593, 96739, 105031, 120233, 134053, 145109, 167221, 179659, 182423, 186569, 187951, 192097, 194861, 212827, 216973, 233557, 281927 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Note that all zeros of A046694(n) have the indices equal to the terms of all arithmetic progressions of the type k*p, where primes p belong to a(n). Thus A046694(k*a(n)) = 0 for all integer k > 0.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Ramanujan's Tau Function.

EXAMPLE

a(1) = 1381 = 2*691 - 1 is a first prime of the form 2m*691 - 1.

MATHEMATICA

Select[ 2*691*Range[ 1000 ] - 1, PrimeQ[ # ] & ]

Select[Table[1382 n - 1, {n, 0, 300}], PrimeQ] (* Vincenzo Librandi, Nov 07 2014 *)

PROG

(MAGMA) [a: n in [0..250] | IsPrime(a) where a is 1382*n-1]; // Vincenzo Librandi, Nov 07 2014

CROSSREFS

Cf. A046694 = Ramanujan tau numbers mod 691 = sum of 11th power of divisors mod 691.

Cf. A121733 = Numbers n such that two consecutive Ramanujan tau numbers are congruent mod 691.

Cf. A121734 = Ramanujan tau numbers such that A000594[n] == A000594[n+1] mod 691.

Cf. A121742 = Numbers n such that three consecutive Ramanujan tau numbers are congruent mod 691.

Cf. A121743 = Values of the Ramanujan tau triples mod 691 such that three consecutive Ramanujan tau numbers are congruent mod 691.

Cf. A134670 = Least number k such that A046694 has a string of n consecutive zeros starting with A046694(k).

Sequence in context: A020406 A277632 A241483 * A161192 A134670 A250367

Adjacent sequences:  A134668 A134669 A134670 * A134672 A134673 A134674

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Nov 05 2007

STATUS

approved

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Last modified January 19 08:18 EST 2022. Contains 350464 sequences. (Running on oeis4.)