id:A073772 - OEIS Search Results

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Number of highly composite numbers (HCNs) between the n-th highly composite number k and 2*k if 2*k is a highly composite number, or -1 if 2*k is not a highly composite number.

+0
1

0, 0, -1, 0, 0, 1, -1, -1, 0, 1, 1, -1, 0, -1, 1, 1, -1, 0, 1, 1, 1, -1, -1, 2, 2, -1, -1, 1, 1, 1, 2, -1, 2, 2, -1, -1, -1, 1, 1, 1, 2, -1, 2, 2, -1, 2, 2, 2, -1, -1, 2, -1, 2, -1, 2, 2, -1, 2, 2, 2, -1, -1, 2, 2, 2, -1, 2, 3, -1, -1, 2, 2, 2, -1, -1, 1, 1, 1, 1, -1, -1, 3, 3, 3, 3, -1, -1, 2, 2, 2, -1, 1, 1, -1, 3, 3, 3, 3 (list; graph; listen)

	OFFSET	`1,24`
	COMMENT	`If 2A002182(n) = A002182(m) then a(n) = m - n - 1; if 2A002182(n) is not a highly composite number then a(n) = -1. The zero terms correspond to the terms of A072938, the negative terms correspond to the terms of A073771. The terms were determined by means of A. Flammenkamp's list (cf. Links).`
	LINKS	`Achim Flammenkamp Highly Composite Numbers`
	EXAMPLE	`a(3) = -1 since 4 is the third highly composite number and 24 = 8 is not a highly composite number; a(6) = 1 since 24 is the sixth highly composite number, 224 = 48 is the eighth highly composite number and the highly composite number 36 is between them; a(13) = 0 since 360 is the 13th highly composite number, 2*360 = 720 is the 14th highly composite number and there is no highly composite number between them.`
	CROSSREFS	`Cf. A002182, A072938, A073771.` `Sequence in context: A099564 A126389 A105551 this_sequence A164562 A058188 A070000` `Adjacent sequences: A073769 A073770 A073771 this_sequence A073773 A073774 A073775`
	KEYWORD	`sign`
	AUTHOR	`Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Aug 19 2002`

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Last modified December 5 23:38 EST 2009. Contains 170428 sequences.

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