%I #16 Sep 08 2022 08:46:06
%S 1,11,137,363,7129,83711,1145993,1195757,42142223,275295799,18858053,
%T 444316699,34052522467,312536252003,9227046511387,290774257297357,
%U 53676090078349,54437269998109,2040798836801833,2066035355155033,85691034670497533
%N First bisection of harmonic numbers (numerators).
%C Numerator of H(2n+1), where H(n) = sum_{k=1..n} 1/k.
%C It can be noted that the second row of the Akiyama-Tanigawa transform of the fractions A232180/A232181 has a simple expression: -5/6, -9/10, -13/14, -17/18, -21/22, ... are of the form -(4*k+5)/(4*k+6).
%F a(n) ~ exp(2n).
%t a[n_] := HarmonicNumber[2*n-1] // Numerator; Table[a[n], {n, 1, 25}]
%o (Magma) [Numerator(HarmonicNumber(2*n-1)): n in [1..30]]; // _Bruno Berselli_, Nov 20 2013
%Y Cf. A001008, A002547, A093158, A175441, A232181 (denominators).
%K nonn,frac,easy
%O 1,2
%A _Jean-François Alcover_ and _Paul Curtz_, Nov 20 2013