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Search: id:A157852
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| A157852 |
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Absolute value of limit_{N -> infinity} (integral((-1)^x*x^(1/x),x=1..2*N). |
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+0 2
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OFFSET
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1,1
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COMMENT
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The continuous counterpart of 1^(1/1)-2^(1/2)+3^(1/3)-4^(1/4)...2*integer as n->infinity.
It is hard to integrate and very slow to converge.
From a numerical integration of the first 5 to 8 periods of the exp(i*pi*x) and estimation of the remainder with a mixed Filon-Euler-Maclaurin approach collecting up to the 5th order of the derivatives, we get 0.68765236884 (up to 6th order 0.68765236894, up to 7th order 0.68765236893), all numbers rounded. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 23 2009]
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LINKS
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M. R. Burns, Used with other constants to converge closely to rational numbers.
M. R. Burns, Author's public inquiry 1
M. R. Burns, Author's public inquiry 2
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EXAMPLE
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After integrating from 1 to 5 Million the integral~= 0.6876533456.
After integrating from 1 to 10 Million the integral~= 0.6876528792.
After integrating from 1 to 15 Million the integral~= 0.6876527177.
After integrating from 1 to 20 Million the integral~= 0.6876526145.
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CROSSREFS
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Integrating A037077 instead of summing.
Sequence in context: A092294 A097668 A133748 this_sequence A088608 A011481 A100221
Adjacent sequences: A157849 A157850 A157851 this_sequence A157853 A157854 A157855
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KEYWORD
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nonn,more
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AUTHOR
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Marvin Ray Burns (bmmmburns(AT)sbcglobal.net), Mar 07 2009, Mar 11 2009, Mar 13 2009
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EXTENSIONS
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Edited by N. J. A. Sloane, Mar 13 2009
Corrected and edited by Marvin Ray Burns (bmmmburns(AT)sbcglobal.net), Apr 03 2009
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