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Revision History for A087491 (Underlined text is an addition; strikethrough text is a deletion.)

Showing entries 1-10 | older changes
A087491 Decimal expansion of the Khinchin harmonic mean K_{-1}.
(history; published version)
#20 by Joerg Arndt at Mon Aug 09 01:11:16 EDT 2021
STATUS

reviewed

approved

#19 by Hugo Pfoertner at Sun Aug 08 23:49:22 EDT 2021
STATUS

proposed

reviewed

#18 by Jianing Song at Sun Aug 08 23:12:30 EDT 2021
STATUS

editing

proposed

#17 by Jianing Song at Sun Aug 08 23:11:23 EDT 2021
COMMENTS

Khinchin's constant is K_0. (A002210).

LINKS

Wikipedia, <a href="http://en.wikipedia.org/wiki/Khinchin%27s_constant">Khinchin's constant</a>

FORMULA

Equals (Sum_{n>=1} -log2(1 - 1/(n+1)^2) * n^(-1))^(-1). - Jianing Song, Aug 08 2021

STATUS

approved

editing

#16 by N. J. A. Sloane at Sun Dec 10 20:48:55 EST 2017
STATUS

reviewed

approved

#15 by Robert G. Wilson v at Sun Dec 10 17:31:15 EST 2017
STATUS

proposed

reviewed

#14 by Eric W. Weisstein at Sun Dec 10 11:15:30 EST 2017
STATUS

editing

proposed

#13 by Eric W. Weisstein at Sun Dec 10 11:15:28 EST 2017
MATHEMATICA

RealDigits[Log[2]/NSum[Log[(1 - 1/(n + 1)^2)^(-1/n)], {n, Infinity}, NSumTerms -> 10^4, WorkingPrecision -> 250, PrecisionGoal -> 110]][[1, ;; 100]] (* Eric W. Weisstein, Dec 10 2017 *)

#12 by Eric W. Weisstein at Sun Dec 10 10:54:21 EST 2017
NAME

Decimal expansion of the Khinchin harmonic mean K_{-1}.

MATHEMATICA

digits = 102; exactEnd = 1000; f[n_] = (1 - 1/(n + 1)^2)^(-1/n); s[n_] = Series[Log[f[n] ], {]], {n, Infinity, digits}] // Normal // N[#, digits]&; ] &; exactSum = Sum[Log[f[n]] , {]], {n, 1, exactEnd}] // N[#, digits]&; ] &; extraSum = Sum[s[n] , {], {n, exactEnd + 1, Infinity}] // N[#, digits]&; ] &; A087491 = Log[2]/(exactSum + extraSum) // RealDigits // First (* Jean-François Alcover, Feb 06 2013 *)

STATUS

approved

editing

#11 by Jon E. Schoenfield at Thu Aug 13 19:48:45 EDT 2015
STATUS

editing

approved

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Last modified August 29 11:12 EDT 2024. Contains 375512 sequences. (Running on oeis4.)