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%I
%S 2,24,72,2880,800,362880,169344
%N Denominators of a sequence leading to gamma = A001620.
%C gamma = 1/2 + 1/24 + 1/72 + 19/2880 + 3/800 + 863/362880 + 275/169344 + ... = (A002206 unsigned=reduced A141417(n+1)/A091137(n+1))/a(n) is an old formula based on Gregory's A002206/A002207.
%C This formula for Euler's constant was discovered in 1924 by the Dutch mathematician Jan C. Kluyver (1860-1932). See reference below. - Hans J. H. Tuenter, Mar 06 2012
%C 2*A001620(n) is not in OEIS.
%H M. Coffey and J. Sondow, <a href="http://arxiv.org/abs/1202.3093">Rebuttal of Kowalenko's paper as concerns the irrationality of Euler's constant</a>, Acta Appl. Math., 121 (2012), 1-3.
%H J. C. Kluyver, <a href="http://www.dwc.knaw.nl/DL/publications/PU00015025.pdf">Euler's constant and natural numbers</a>, Proc. Kon. Ned. Akad. Wet., 27(1-2) (1924), 142-144.
%F a(n) = (n+1) * A002207.
%e a(0)=1*2, a(1)=2*12, a(2)=3*24, a(3)=4*720.
%t g[n_] := Sum[ BernoulliB[j]/j * StirlingS1[n, j-1], {j, 1, n+1}] / n! ; a[n_] := (n+1)*Denominator[g[n]]; Table[a[n], {n, 0, 10}] (* _Jean-François Alcover_, Aug 10 2012 *)
%K nonn
%O 0,1
%A _Paul Curtz_, Sep 11 2011
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