id:A023215 - OEIS Search Results

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Numbers n such that n and 4n + 7 both prime.

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3, 13, 19, 31, 43, 61, 103, 109, 139, 163, 241, 271, 313, 373, 379, 499, 523, 601, 613, 631, 643, 673, 709, 733, 739, 751, 769, 811, 823, 829, 883, 1021, 1033, 1051, 1063, 1069, 1129, 1171, 1231, 1249, 1291, 1381, 1459, 1483, 1531, 1549, 1579, 1621, 1663 (list; graph; listen)

	OFFSET	`1,1`
	MATHEMATICA	`f[n_]:=PrimeQ[4*n+7]; lst={}; Do[p=Prime[n]; If[f[p], AppendTo[lst, p]], {n, 6!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 03 2009]`
	CROSSREFS	`Sequence in context: A038974 A079419 A117300 this_sequence A023239 A018621 A024469` `Adjacent sequences: A023212 A023213 A023214 this_sequence A023216 A023217 A023218`
	KEYWORD	`nonn`
	AUTHOR	`David W. Wilson (davidwwilson(AT)comcast.net)`

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Last modified December 10 12:32 EST 2009. Contains 170569 sequences.

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