id:A099049 - OEIS Search Results

Search: id:A099049

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Numbers n such that n-1 and n+1 are both prime or both composite.

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4, 5, 6, 7, 9, 11, 12, 13, 15, 17, 18, 19, 21, 23, 25, 26, 27, 29, 30, 31, 33, 34, 35, 37, 39, 41, 42, 43, 45, 47, 49, 50, 51, 53, 55, 56, 57, 59, 60, 61, 63, 64, 65, 67, 69, 71, 72, 73, 75, 76, 77, 79, 81, 83, 85, 86, 87, 89, 91, 92, 93, 94, 95, 97, 99, 101, 102, 103, 105, 107 (list; graph; listen)

	OFFSET	`1,1`
	PROGRAM	`(PARI) for(n=3, 200, s=isprime(n-1)+isprime(n+1); if(s<>1, print1(n, ", ")))`
	CROSSREFS	`Sequence in context: A075862 A088685 A022299 this_sequence A036668 A010381 A095033` `Adjacent sequences: A099046 A099047 A099048 this_sequence A099050 A099051 A099052`
	KEYWORD	`nonn`
	AUTHOR	`Rick L. Shepherd (rshepherd2(AT)hotmail.com), Nov 13 2004`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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