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A075180 Denominators from e.g.f. 1/(1-exp(-x)) - 1/x. +0
2
2, 12, 1, 120, 1, 252, 1, 240, 1, 132, 1, 32760, 1, 12, 1, 8160, 1, 14364, 1, 6600, 1, 276, 1, 65520, 1, 12, 1, 3480, 1, 85932, 1, 16320, 1, 12, 1, 69090840, 1, 12, 1, 541200, 1, 75852, 1, 2760, 1, 564, 1, 2227680 (list; graph; listen)
OFFSET

0,1

COMMENT

Denominators of Riemann's -Zeta(-n), n>=0.

Numerators are +1, A060054(n+1), n>=1.

REFERENCES

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 807, combined eqs. 23.2.11,14 and 15.

LINKS

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 807, combined eqs. 23.2.11,14 and 15.

FORMULA

a(n)=denominator(-Zeta(-n))=denominator(((-1)^(n+1))*B(n+1)/(n+1)), n>=0, with Riemann's zeta function and the Bernoulli numbers B(n).

a(n)= denominators from e.g.f. (B(-x)-1)/x, with B(x)= x/(exp(x)-1), e.g.f. for Bernoulli numbers A027641(n)/A027642(n), n>=0.

EXAMPLE

1/2, 1/12, 0, -1/120, 0, 1/252, 0, -1/240, 0, 1/132, 0, -691/32760,...

MAPLE

a := n -> denom(bernoulli(n+1, 1)/(n+1)); [From Peter Luschny (peter(AT)luschny.de), Apr 22 2009]

MATHEMATICA

a[m_] := Sum[(-2)^(-k-1) k! StirlingS2[m, k], k, 0, m}]/(2^(m+1)-1); Table[Denominator[a[i]], {i, 0, 20}] [From Peter Luschny (peter(AT)luschny.de), Apr 29 2009]

CROSSREFS

A060054, A006232 with A006233.

Sequence in context: A082185 A113491 A107773 this_sequence A167164 A010239 A128268

Adjacent sequences: A075177 A075178 A075179 this_sequence A075181 A075182 A075183

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Sep 06, 2002

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Last modified December 1 13:27 EST 2009. Contains 167806 sequences.


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