id:A100915 - OEIS Search Results

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Numbers n such that n plus n-th semiprime is semiprime.

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5

4, 6, 9, 12, 16, 18, 19, 20, 24, 29, 31, 34, 35, 39, 40, 44, 46, 49, 51, 54, 55, 72, 73, 76, 79, 80, 81, 84, 87, 91, 93, 94, 96, 98, 110, 113, 116, 120, 128, 130, 136, 137, 148, 150, 154, 159, 165, 168, 170, 172, 175, 188, 190, 191, 199, 200, 206, 215, 217, 220, 230 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`This is the semiprime analogue of A064402.`
	LINKS	`Eric Weisstein, World of Mathematics, Semiprime.`
	FORMULA	`a(n) = A100466(n) - A100916(n) = A100466(n) - A001358(A100915(n)).`
	EXAMPLE	`a(3) = 9 because 9 + semiprime(9) = 9 + 25 = 34 is semiprime.`
	CROSSREFS	`Cf. A001358, A064402, A100493, A100466, A100467, A100916.` `Sequence in context: A162735 A024675 A163656 this_sequence A144922 A088765 A078782` `Adjacent sequences: A100912 A100913 A100914 this_sequence A100916 A100917 A100918`
	KEYWORD	`easy,nonn`
	AUTHOR	`Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 26 2004`

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Last modified November 23 17:09 EST 2009. Contains 167438 sequences.

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