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A053355 Numbers k such that 277*2^k + 1 is prime. 0
2, 6, 8, 18, 20, 22, 36, 62, 108, 120, 162, 180, 222, 450, 530, 706, 1028, 1200, 1296, 1362, 2280, 3788, 7130, 8082, 8150, 10226, 10302, 11578, 48426, 57890 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..30.

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300

Wilfrid Keller, List of primes k.2^n - 1 for k < 300

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

MATHEMATICA

Select[Range[5*10^3], PrimeQ[277*2^# + 1] &] (* G. C. Greubel, May 24 2018 *)

PROG

(PARI) is(n)=ispseudoprime(277*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

(MAGMA) [n: n in [1..300] | IsPrime(277*2^n+1)];  // G. C. Greubel, May 24 2018

CROSSREFS

Sequence in context: A137848 A182629 A183212 * A233572 A005823 A259026

Adjacent sequences:  A053352 A053353 A053354 * A053356 A053357 A053358

KEYWORD

hard,nonn,changed

AUTHOR

N. J. A. Sloane, Dec 29 1999

STATUS

approved

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Last modified December 17 05:36 EST 2018. Contains 318192 sequences. (Running on oeis4.)