OFFSET
0,1
COMMENTS
Asymptotic expansion: B(2*n,n) / n^(2*n) ~ c0 + c1/n + c2/n^2 + ..., where
c0 = A349004
c1 = -0.11332842437985451266688985513574347679739396134203607414578687657...
c2 = -0.02939332883129837328682967905833985820907100422772261310141242364...
In general, for k>=1, B(k*n,n) / n^(k*n) ~ k/(exp(k) - 1).
LINKS
William Bell, Problem 4312, Crux Mathematicorum, Vol. 44, No. 2 (2018), pp. 69 and 71; Solution to Problem 4312, ibid., Vol. 45, No. 2 (2019), pp. 92-93.
Eric Weisstein's World of Mathematics, Bernoulli Polynomial.
Wikipedia, Bernoulli Polynomials.
FORMULA
Equals 2/(exp(2)-1).
From Peter Luschny, Nov 05 2021: (Start)
Equals lim_{n->oo} (1/n) * Sum_{k=0..n-1} B(2*n, 1 + k/n)) by J. L. Raabe's multiplication theorem.
Equals -2 * lim_{n->oo} HurwitzZeta(1 - 2*n, n) * n^(1 - 2*n). (End)
Equals A073747 - 1. - Alois P. Heinz, Nov 05 2021
Equals Sum_{k>=1} tanh(1/2^k)/2^k (Bell, 2018). - Amiram Eldar, Apr 12 2022
EXAMPLE
0.313035285499331303636161246930847832912013941240452655543152967567084...
MATHEMATICA
$MaxExtraPrecision = 1000; funs[n_] := BernoulliB[2 n, n]/n^(2 n); Do[Print[N[Sum[(-1)^(m + j)*funs[j*Floor[1000/m]] * j^(m - 1)/(j - 1)!/(m - j)!, {j, 1, m}], 110]], {m, 10, 100, 10}]
RealDigits[2/(E^2 - 1), 10, 110][[1]]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Vaclav Kotesovec, Nov 05 2021
STATUS
approved