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A002547 Numerator of {n-th harmonic number H(n) divided by (n+1)}: a(n) = Numerator[HarmonicNumber[n]/(n+1)], H(n) = HarmonicNumber[n] = A001008(n)/A002805(n).
(Formerly M4765 N2036)
+0
3
1, 1, 11, 5, 137, 7, 363, 761, 7129, 671, 83711, 6617, 1145993, 1171733, 1195757, 143327, 42142223, 751279, 275295799, 55835135, 18858053, 830139, 444316699, 269564591, 34052522467, 34395742267, 312536252003, 10876020307, 9227046511387, 300151059037 (list; graph; listen)
OFFSET

2,3

COMMENT

Numerators of coefficients for numerical differentiation.

Numerator of u(n)=sum(k=1,n,1/k/(n-k)) (u(n) is asymptotic to 2*log(n)/n) - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 12 2003

REFERENCES

W. G. Bickley and J. C. P. Miller, Numerical differentiation near the limits of a difference table, Phil. Mag., 33 (1942), 1-12 (plus tables).

A. N. Lowan, H. E. Salzer and A. Hillman, A table of coefficients for numerical differentiation, Bull. Amer. Math. Soc., 48 (1942), 920-924.

LINKS

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

FORMULA

G.f.: (-ln(1-x))^2 (for fractions A002547(n)/A002548(n))

A002547(n)/A002548(n)=2 stirling1(n+2, n)(-1)^n/(n+2)!

EXAMPLE

E.g. H(n) = Sum[1/i,{i,1,n}] begins 1, 3/2, 11/6, 25/12, ... so H(n)/(n+1) begins 1/2, 1/2, 11/24, 5/12, ... so a(4) = 5.

MAPLE

with(combinat):seq(numer(stirling1(j+2, 2)/(j+2)!*2!*(-1)^j), j=0..50);

MATHEMATICA

Numerator[HarmonicNumber[n]/(n+1)]

CROSSREFS

Cf. A002548.

Cf. A001008, A002805.

Sequence in context: A127820 A120831 A038319 this_sequence A090840 A080501 A122098

Adjacent sequences: A002544 A002545 A002546 this_sequence A002548 A002549 A002550

KEYWORD

nonn,frac

AUTHOR

njas

EXTENSIONS

More terms, GF, formula, Maple code from Barbara Margolius (b.margolius(AT)math.csuohio.edu), Jan 19, 2002

Simpler definition from Alexander Adamchuk (alex(AT)kolmogorov.com), Oct 31 2004

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Last modified August 29 17:54 EDT 2008. Contains 143238 sequences.


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