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A073100
Denominator of b(n) = n * Sum_{k=2^n..2^(n+1)-1} (-1)^k/k.
2
6, 210, 120120, 18050444111700, 118226688410282226751136160, 1112813007583117631616979100370019711878239390670756000, 1191035057635417333689929196555456096447880322064975132139675263681349241137859495385119040334214863238544000
OFFSET
1,1
LINKS
G. Vacca, A new series for the Eulerian constant gamma=.577..., Quart. J. Pure Appl. Math., Vol. 41 (1910), pp. 363-368.
FORMULA
Sum_{k>=1} b(k) = gamma = 0.5772... (A001620).
MATHEMATICA
a[n_] := Denominator[n * Sum[(-1)^k/k, {k, 2^n, 2^(n+1)-1}]]; Array[a, 7] (* Amiram Eldar, May 19 2022 *)
PROG
(PARI) a(n)=denominator( n*sum(k=2^n, 2^(n+1)-1, (-1)^k/k))
CROSSREFS
Cf. A001620, A073099 (numerators).
Sequence in context: A346017 A099788 A126676 * A093536 A002037 A071367
KEYWORD
easy,frac,nonn
AUTHOR
Benoit Cloitre, Aug 18 2002
STATUS
approved