id:A056956 - OEIS Search Results

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Numbers n such that 6n+1 and 6n+5 are both primes.

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1, 2, 3, 6, 7, 11, 13, 16, 17, 18, 21, 27, 32, 37, 38, 46, 51, 52, 58, 63, 66, 73, 76, 77, 81, 83, 102, 107, 112, 123, 126, 128, 137, 142, 143, 146, 147, 151, 156, 161, 168, 181, 182, 202, 213, 216, 217, 237, 238, 241, 247, 248, 258, 261, 263, 266, 268, 277, 282 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`Note that if prime p>3 then p mod 6 = 1 or 5.`
	FORMULA	`a(n) = (A023200(n+1)-1)/6 = (A046132(n+1)-5)/6 = A047847(n+1)/3`
	EXAMPLE	`a(2)=2 since 62+1=13 and 62+5=17 are both prime.`
	MATHEMATICA	`Select[Range[300], And @@ PrimeQ /@ ({1, 5} + 6#) &] (Chandler)`
	CROSSREFS	`Cf. A002822, A024898, A024899, A059325.` `Sequence in context: A024561 A113545 A056825 this_sequence A002256 A008765 A018468` `Adjacent sequences: A056953 A056954 A056955 this_sequence A056957 A056958 A056959`
	KEYWORD	`nonn`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Jul 18 2000`
	EXTENSIONS	`Edited by njas, Nov 07 2006`

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Last modified September 6 16:04 EDT 2008. Contains 143483 sequences.

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