cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A060746 Absolute value of numerator of non-Euler-constant term of Laurent expansion of Gamma function at s = -n.

Original entry on oeis.org

0, 1, 3, 11, 25, 137, 49, 121, 761, 7129, 7381, 83711, 86021, 1145993, 1171733, 1195757, 2436559, 42142223, 14274301, 275295799, 11167027, 18858053, 6364399, 444316699, 269564591, 34052522467, 34395742267, 312536252003
Offset: 0

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Author

Sen-Peng Eu, Apr 23 2001

Keywords

Comments

If you start with log(z) and integrate it n times in succession, then you get z^n*log(z)/n! - K(n)*z^n where K(1)=1, K(2)=3/4, K(3)=11/36, K(4)=25/288, K(5)=137/7200, K(6)=49/14400, etc. - Warren D. Smith, Jan 01 2006
It appears that, if we discard the first term and set a(0)=1, then a(n) = denominator of n!(h(n)/h(n+1)) where h(n) is the n-th harmonic number = Sum_{k=1..n} 1/k. - Gary Detlefs, Sep 09 2010

Examples

			series(GAMMA(s), s=-4,1 ) = series(1/24*(s+4)^(-1)+(25/288-1/24*gamma)+O((s+4)),s=-4,1). Hence a(4)=25 series(GAMMA(s), s=-5,1 ) = series(-1/120*(s+5)^(-1)+(-137/7200+1/120*gamma)+O((s+5)),s=-5,1). Hence a(5)=137.
		

Formula

Conjecture: a(n) = lcm(Wolstenholme(n), n!)/n!, cf. A001008. - Vladeta Jovovic, May 20 2004
Conjecture: a(n) = numerator(harmonic(n)/(n-1)!) for n >= 1. - Peter Luschny, May 13 2023