A106405 - OEIS

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A106405

Number of odd semiprimes dividing n.

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 2, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 2, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 2, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 2, 1, 0, 1, 0, 1, 0, 0, 1, 2, 1, 0, 1, 0, 0, 3 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,45`
	COMMENTS	`a(n) = A086971(n) - A106404(n);` `a(A046315(n)) = 1; a(A093641(n)) = 0; a(A105441(n)) > 0.`
	EXAMPLE	`a(105) = #{15, 21, 35} = #{35, 37, 5*7} = 3.`
	CROSSREFS	`Cf. A001227, A000005.` `Sequence in context: A030216 A159459 A143078 * A089310 A129753 A147693` `Adjacent sequences: A106402 A106403 A106404 * A106406 A106407 A106408`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 02 2005`

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Last modified February 16 09:00 EST 2012. Contains 205904 sequences.