The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A004041 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A004041

Scaled sums of odd reciprocals: a(n) = (2*n + 1)!!*(Sum_{k=0..n} 1/(2*k + 1)).
(history; published version)

#51 by Michael De Vlieger at Sat Dec 28 00:06:48 EST 2024

STATUS

reviewed

approved

#50 by Andrew Howroyd at Fri Dec 27 23:12:14 EST 2024

STATUS

proposed

reviewed

#49 by Jason Yuen at Fri Dec 27 23:04:10 EST 2024

STATUS

editing

proposed

#48 by Jason Yuen at Fri Dec 27 23:03:50 EST 2024

FORMULA

Sum_{n>=1} a(n-1)/(n!*n*2^n)) = (Pi/2)^2. - Philippe Deléham, Aug 12 2003

STATUS

approved

editing

#47 by Michel Marcus at Fri Feb 04 02:16:10 EST 2022

STATUS

reviewed

approved

#46 by Joerg Arndt at Fri Feb 04 02:15:26 EST 2022

STATUS

proposed

reviewed

#45 by Andrew Howroyd at Thu Feb 03 18:04:09 EST 2022

STATUS

editing

proposed

#44 by Andrew Howroyd at Thu Feb 03 18:03:51 EST 2022

DATA

1, 4, 23, 176, 1689, 19524, 264207, 4098240, 71697105, 1396704420, 29985521895, 703416314160, 17901641997225, 491250187505700, 14459713484342175, 454441401368236800, 15188465029114325025, 537928935889764226500, 20125013723397976152375, 793076329745158961502000, 32835960506324395192397625, 1425059372229636981876538500, 64691533780014247694392179375, 3065875878996295899584090040000, 151420486263592933203160319600625, 7780880640889186865414631774022500, 415366901880870214741701713217114375, 23003131682876257287154084374219150000, 1319865870292508416567609767430773815625, 78367266116266016395879112890131744262500

EXTENSIONS

More terms from n=18 to 30. Edited by Anthony Frazier

STATUS

proposed

editing

Discussion

Thu Feb 03

18:04

Andrew Howroyd: Unpicked.

#43 by Anthony Frazier at Thu Feb 03 17:58:49 EST 2022

STATUS

editing

proposed

Discussion

Thu Feb 03

18:02

Andrew Howroyd: We only want 260 chars in the DATA field. This one was already full. It also has a b-file with 403 terms - see first link by Seiichi Manyama, so you are not adding more terms here.

#42 by Anthony Frazier at Thu Feb 03 17:58:45 EST 2022

DATA

EXTENSIONS

More terms from n=18 to 30. Edited by Anthony Frazier

STATUS

approved

editing