id:A156658 - OEIS Search Results

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Primes p such that also 2*p+1 or (p-1)/2 is prime.

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3

2, 3, 5, 7, 11, 23, 29, 41, 47, 53, 59, 83, 89, 107, 113, 131, 167, 173, 179, 191, 227, 233, 239, 251, 263, 281, 293, 347, 359, 383, 419, 431, 443, 467, 479, 491, 503, 509, 563, 587, 593, 641, 653, 659, 683, 719, 743, 761, 809, 839, 863, 887, 911, 953, 983, 1013 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`Union of A005384 and A005385;` `A156660(a(n)) + A156659(a(n)) > 0;` `primes occuring in Cunningham chains of the first kind.` `A156876 gives the number of these numbers <= n. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 18 2009]`
	LINKS	`Wikipedia, Sophie Germain prime` `Wikipedia, Safe prime` `Wikipedia, Cunningham chain`
	CROSSREFS	`A059500.` `Sequence in context: A089392 A089695 A070027 this_sequence A118723 A118721 A094318` `Adjacent sequences: A156655 A156656 A156657 this_sequence A156659 A156660 A156661`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 13 2009`

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Last modified December 20 13:54 EST 2009. Contains 171081 sequences.

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