OFFSET
0,2
COMMENTS
Conjecture: For n > 0, a(n) is a Zumkeller number (A083207). Verified form all n in [2,19]. - Ivan N. Ianakiev, Feb 17 2020
LINKS
Iaroslav V. Blagouchine and Marc-Antoine Coppo, A note on some constants related to the zeta-function and their relationship with the Gregory coefficients, arXiv:1703.08601 [math.NT], 2017. Also The Ramanujan Journal 47.2 (2018): 457-473. See Cor. 2 to Th. 2. (a(7) is wrong in the printed version.)
FORMULA
MATHEMATICA
g[n_] := -(-1)^n*Sum[StirlingS1[n, j]/(j + 1), {j, 1, n}]/n!; Flatten[{1, Table[Denominator[2*Sum[g[k]*g[n + 2 - k], {k, 1, n}]/(n + 1)], {n, 1, 25}]}] (* Vaclav Kotesovec, Feb 16 2020 *)
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
N. J. A. Sloane, Feb 16 2020
EXTENSIONS
a(7) corrected by and more terms from Vaclav Kotesovec, Feb 16 2020
STATUS
approved