A050895 - OEIS

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A050895

Numbers k such that 273*2^k-1 is prime.

2, 6, 10, 15, 22, 26, 31, 42, 47, 98, 107, 123, 126, 175, 178, 203, 223, 230, 239, 279, 371, 402, 519, 607, 755, 830, 871, 927, 980, 1527, 1770, 2007, 2218, 2247, 2250, 3982, 4367, 4510, 9716, 13018, 20906, 26340, 40186, 63332, 84599, 119743, 156155, 206118, 238687 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,1`
	LINKS	`Table of n, a(n) for n=1..49.` `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` `Kosmaj, Riesel list k<300.` `Index entries for sequences of n such that k2^n-1 (or k2^n+1) is prime`
	MATHEMATICA	`Select[Range[1000], PrimeQ[2732^# - 1] & ] ( Robert Price, Dec 30 2018 *)`
	PROG	`(PARI) is(n)=ispseudoprime(273*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017`
	CROSSREFS	`Sequence in context: A331250 A186783 A133931 * A184426 A293408 A357387` `Adjacent sequences: A050892 A050893 A050894 * A050896 A050897 A050898`
	KEYWORD	`hard,nonn`
	AUTHOR	`N. J. A. Sloane, Dec 29 1999`
	EXTENSIONS	`More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008` `a(48)-a(49) from the Wilfrid Keller link by Robert Price, Dec 30 2018`
	STATUS	`approved`

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Last modified March 5 01:58 EST 2023. Contains 360893 sequences. (Running on oeis4.)