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Numerator of 2 * H(n,2,1), a generalized harmonic number. See A075135. Also 2 * A025550.
9

%I #4 Mar 30 2012 18:59:43

%S 2,8,46,352,1126,13016,176138,182144,3186538,62075752,63461422,

%T 1488711776,7577414602,23104065256,680057071574,21372905414144,

%U 21646396991594,21904260478904,819482859775298,828045249930848

%N Numerator of 2 * H(n,2,1), a generalized harmonic number. See A075135. Also 2 * A025550.

%t Table[ Numerator[ Sum[1/i, {i, 1/2, n}]], {n, 1, 20}]

%Y The denominators are in A025547.

%Y Cf. A025550, A075135.

%Y Contribution from _Johannes W. Meijer_, Jun 08 2009: (Start)

%Y Not always equal to the second left hand column of A161198 triangle divided by A025549.

%Y (End)

%K easy,frac,nonn

%O 1,1

%A _Robert G. Wilson v_, Aug 27 2002