id:A047949 - OEIS Search Results

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a(2) = a(3) = 0; for n >= 4, a(n) = largest m such that n-m and n+m are both primes, or -1 if no such m exists.

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0, 0, 1, 2, 1, 4, 5, 4, 7, 8, 7, 10, 9, 8, 13, 14, 13, 12, 17, 16, 19, 20, 19, 22, 21, 20, 25, 24, 23, 28, 29, 28, 27, 32, 31, 34, 35, 34, 33, 38, 37, 40, 39, 38, 43, 42, 41, 30, 47, 46, 49, 50, 49, 52, 53, 52, 55, 54, 53, 48, 51, 50, 45, 62, 61, 64, 63, 62, 67, 68, 67, 66 (list; graph; listen)

	OFFSET	`2,4`
	LINKS	`T. D. Noe, Table of n, a(n) for n=2..10000`
	EXAMPLE	`49-30=19 and 49+30=79 are primes, so a(49)=30.`
	CROSSREFS	`Cf. A047160.` `Sequence in context: A165050 A165042 A165046 this_sequence A075423 A144774 A074720` `Adjacent sequences: A047946 A047947 A047948 this_sequence A047950 A047951 A047952`
	KEYWORD	`easy,nice,nonn`
	AUTHOR	`Lior Manor (lior.manor(AT)gmail.com)`
	EXTENSIONS	`Corrected by Harvey P. Dale (hpd1(AT)is2.nyu.edu), Dec 21 2000`

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Last modified December 20 00:58 EST 2009. Contains 171054 sequences.

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