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Least natural number k such that n + sum{i=1,...,k} Safe_Prime[i] is prime, if such k exists; = 0 otherwise.

+0
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2, 1, 10, 5, 2, 1, 2, 1, 12, 5, 2, 1, 4, 1, 4, 5, 2, 1, 2, 3, 4, 7, 12, 1, 2, 1, 4, 7, 2, 3, 2, 1, 4, 5, 2, 1, 4, 1, 6, 17, 2, 1, 4, 3, 6, 5, 2, 1, 2, 3, 4, 11, 12, 1, 2, 1, 4, 5, 2, 3, 2, 1, 4, 5, 14, 1, 2, 1, 10, 5, 2, 7, 10, 1, 6, 7, 2, 1, 8, 3, 4, 7, 26, 1, 2, 3, 6, 5, 2, 3, 2, 1, 4, 11, 2, 1, 2, 1, 6 (list; graph; listen)

	OFFSET	`0,1`
	COMMENT	`Safe_Prime[i] denotes the i-th safe prime (A005385). Conjecture: a(n) is nonzero for all n, so every n can be represented as the difference between a prime and a partial sum of the safe primes series. See A066753 for a similar conjecture.`
	EXAMPLE	`4 + (5 + 7 + 11 + 23 + 47) = 97, a prime, and 5 consecutive safe primes, starting from the first safe prime 5, are needed to achieve this. Hence a(4) = 5.`
	CROSSREFS	`Cf. A005385, A066753.` `Sequence in context: A121334 A126450 A112333 this_sequence A004747 A081099 A122017` `Adjacent sequences: A066865 A066866 A066867 this_sequence A066869 A066870 A066871`
	KEYWORD	`nonn`
	AUTHOR	`Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Jan 21 2002`

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Last modified August 29 17:54 EDT 2008. Contains 143238 sequences.

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