The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A052456

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A052456

Number of magic series of order n.
(history; published version)

#41 by N. J. A. Sloane at Tue Jan 07 11:42:24 EST 2020

COMMENTS

Henry Bottomley's narrowing gap could be confirmed for 2 < n <= 64. - _Walter Trump (w(AT)trump.de), _, Jan 21 2005

A new algorithm was found by Robert Gerbicz. Now the enumeration of magic series of orders greater than 100 is possible. - _Walter Trump (w(AT)trump.de), _, May 05 2006

Discussion

Tue Jan 07

11:42

OEIS Server: https://oeis.org/edit/global/2840

#40 by Alois P. Heinz at Fri Nov 02 11:17:33 EDT 2018

STATUS

editing

approved

#39 by Alois P. Heinz at Fri Nov 02 11:17:30 EDT 2018

CROSSREFS

Cf. A007785, A052457, A052458. A100568 is the same sequence times n!.

STATUS

approved

editing

#38 by Alois P. Heinz at Wed Oct 31 22:29:44 EDT 2018

STATUS

editing

approved

#37 by Alois P. Heinz at Wed Oct 31 22:29:41 EDT 2018

EXAMPLE

a(3) = 8 since a magic square of order 3 would require a row sum of 15=(1+2+...+9)/3 and there are 8 ways of writing 15 as the sum of three distinct positive numbers up to 9: 1+5+9, 1+6+8, 2+4+9, 2+5+8, 2+6+7, 3+4+8, 3+5+7, 4+5+6.

STATUS

approved

editing

#36 by Alois P. Heinz at Wed Oct 31 22:03:24 EDT 2018

STATUS

editing

approved

#35 by Alois P. Heinz at Wed Oct 31 22:03:22 EDT 2018

CROSSREFS

Diagonal Main diagonal of A204459. - Alois P. Heinz, Jan 18 2012

STATUS

approved

editing

#34 by Alois P. Heinz at Wed Oct 31 12:27:23 EDT 2018

STATUS

editing

approved

#33 by Alois P. Heinz at Wed Oct 31 12:27:21 EDT 2018

COMMENTS

A new algorithm was found by _Robert Gerbicz_. Now the enumeration of magic series of orders greater than 100 is possible. - Walter Trump (w(AT)trump.de), May 05 2006

STATUS

approved

editing

#32 by OEIS Server at Wed Oct 31 12:24:46 EDT 2018

LINKS

T. D. Noe and Alois P. Heinz, <a href="/A052456/b052456_1.txt">Table of n, a(n) for n = 0..150</a> (from Gerbicz and Trump)