id:A121765 - OEIS Search Results

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Numbers n such that 6n-1 is composite while 6n+1 is prime.

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6, 11, 13, 16, 21, 26, 27, 35, 37, 46, 51, 55, 56, 61, 62, 63, 66, 68, 73, 76, 81, 83, 90, 91, 96, 101, 102, 105, 112, 115, 118, 121, 122, 123, 125, 126, 128, 131, 142, 146, 151, 153, 156, 161, 165, 166, 168, 173, 178, 181, 186, 187, 188, 195, 200, 202, 206, 208, 216 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`Entries in A046953 which are not in A060461 or equivalently,entries in A024899 which are not in A002822.`
	MATHEMATICA	`Select[Range[250], ! PrimeQ[6# - 1] && PrimeQ[6# + 1] &] (Chandler)`
	CROSSREFS	`Cf. A121764.` `Sequence in context: A004471 A175021 A046953 this_sequence A102974 A154293 A068308` `Adjacent sequences: A121762 A121763 A121764 this_sequence A121766 A121767 A121768`
	KEYWORD	`nonn`
	AUTHOR	`Lekraj Beedassy (blekraj(AT)yahoo.com), Aug 20 2006`
	EXTENSIONS	`Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Aug 22 2006`

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Last modified December 7 08:40 EST 2009. Contains 170430 sequences.

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