id:A115719 - OEIS Search Results

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Products of two primes that are not Chen primes.

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1849, 2623, 3139, 3397, 3721, 4171, 4429, 4453, 4453, 4819, 5329, 5767, 5917, 6241, 6283, 6493, 7009, 7081, 7439, 7519, 7663, 8137, 8299, 9211, 9409, 9589, 9847, 9943, 9991, 10363, 10553, 10609, 11023, 11653, 11773, 11899, 11911, 11929, 12169, 12629 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`Subset of semiprimes A001358 such that neither prime factor is a Chen prime. See also A109611 (Chen primes: primes p such that p + 2 is either a prime or a semiprime), A102540 (primes that are not Chen primes).`
	FORMULA	`{p*q such that p is in A102540 and q is in A102540}. {s such that s is in A001358 AND p\|s IMPLIES NOT(p is in A109611}.`
	EXAMPLE	`a(1) = 1849 = A102540(1)A102540(1) = 4343.` `a(2) = 2623 = A102540(1)A102540(2) = 4361.` `a(36) = 14701 = A102540(2)A102540(13) = 61 241.`
	CROSSREFS	`Cf. A000040, A001358, A109611, A102540.` `Sequence in context: A080395 A092003 A090783 this_sequence A062670 A031764 A031631` `Adjacent sequences: A115716 A115717 A115718 this_sequence A115720 A115721 A115722`
	KEYWORD	`easy,nonn`
	AUTHOR	`Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 09 2006`

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.

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