The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A048272 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A048272

Number of odd divisors of n minus number of even divisors of n.
(history; published version)

#146 by N. J. A. Sloane at Mon Sep 02 01:12:48 EDT 2024

STATUS

editing

approved

#145 by N. J. A. Sloane at Mon Sep 02 01:12:46 EDT 2024

COMMENTS

An argument by _Gareth McCaughan _ suggests that the average of this sequence is log(2). - Hans Havermann, Feb 10 2013 [Supported by a graph. - Vaclav Kotesovec, Mar 01 2023]

STATUS

approved

editing

#144 by Michel Marcus at Sat Aug 10 03:35:51 EDT 2024

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reviewed

approved

#143 by Joerg Arndt at Sat Aug 10 01:53:54 EDT 2024

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proposed

reviewed

#142 by Jason Yuen at Sat Aug 10 01:44:05 EDT 2024

STATUS

editing

proposed

#141 by Jason Yuen at Sat Aug 10 01:43:39 EDT 2024

COMMENTS

abs(a(n)) = (1/2) * (number of pairs (i,j) satisfying n = i^2 - j^2 and -n <= i,j <= n). - Benoit Cloitre, Jun 14 2003

FORMULA

a(A008586(n)) < 0; a(A005843(a(n)) <= 0; a(A016825(n)) = 0; a(A042968(n)) >= 0; a(A005408(n)) > 0. (End)

STATUS

approved

editing

#140 by Wesley Ivan Hurt at Sat Jun 22 17:24:32 EDT 2024

STATUS

editing

approved

#139 by Wesley Ivan Hurt at Sat Jun 22 17:24:01 EDT 2024

COMMENTS

Inverse Möbius transform of (-1)^(n+1). - Wesley Ivan Hurt, Jun 22 2024

STATUS

approved

editing

#138 by N. J. A. Sloane at Sun Feb 18 12:19:24 EST 2024

STATUS

proposed

approved

#137 by Kevin Ryde at Sat Feb 17 19:12:08 EST 2024

STATUS

editing

proposed