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A050932
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Denominator of (n+1)*Bernoulli(n).
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10
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1, 1, 2, 1, 6, 1, 6, 1, 10, 1, 6, 1, 210, 1, 2, 1, 30, 1, 42, 1, 110, 1, 6, 1, 546, 1, 2, 1, 30, 1, 462, 1, 170, 1, 6, 1, 51870, 1, 2, 1, 330, 1, 42, 1, 46, 1, 6, 1, 6630, 1, 22, 1, 30, 1, 798, 1, 290, 1, 6, 1, 930930, 1, 2, 1, 102, 1, 966, 1, 10, 1, 66, 1, 1919190
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OFFSET
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0,3
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COMMENTS
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Apparently a(n) = denominator(Sum_{k=0..n-1} (-1)^(n-k+1)*E1(n, k+1)/binomial(n, k+1)), where E1(n, k) denotes the first-order Eulerian numbers A123125. - Peter Luschny, Feb 17 2021
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LINKS
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MATHEMATICA
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Denominator/@Table[(n+1)BernoulliB[n], {n, 0, 80}] (* Harvey P. Dale, May 19 2011 *)
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PROG
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(Haskell)
a050932 n = a050932_list !! n
a050932_list = 1 : map (denominator . sum) (zipWith (zipWith (%))
(zipWith (map . (*)) (drop 2 a000142_list) a242179_tabf) a106831_tabf)
(Python)
from sympy import bernoulli, gcd
q = bernoulli(n).q
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CROSSREFS
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Cf. A050925, A000367/A002445, A027641/A027642, A002882, A003245, A127187, A127188, A242179, A106831, A000142, A123125.
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KEYWORD
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nonn,frac,nice,easy
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AUTHOR
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STATUS
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approved
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