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Search: id:A130492
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| A130492 |
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a(n) = denominator of sum{k=1 to n} k^mu(n+1-k), where mu(m) = A008683(m). |
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+0
2
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| 1, 1, 2, 6, 12, 20, 10, 84, 840, 72, 630, 1320, 2772, 1560, 90090, 42, 240240, 1904, 46410, 95760, 639540, 5040, 9699690, 637560, 14316120, 92400, 176125950, 308880, 20078358300, 475020, 33845175, 7447440, 116925953760, 110880, 501401225325
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OFFSET
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1,3
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COMMENT
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Numerator of sum{k=1 to n} k^mu(n+1-k) is A130491(n).
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MAPLE
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A130492 := proc(n) denom(add(k^numtheory[mobius](n+1-k), k=1..n)) ; end: seq(A130492(n), n=1..40) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 16 2007
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CROSSREFS
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Cf. A130491, A080306, A080326.
Sequence in context: A065005 A139084 A086958 this_sequence A139082 A061078 A067114
Adjacent sequences: A130489 A130490 A130491 this_sequence A130493 A130494 A130495
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KEYWORD
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frac,nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), May 29 2007
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 16 2007
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