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Search: id:A097910
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| A097910 |
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Number of parts in all compositions of n into distinct parts. |
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+0
2
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| 1, 1, 5, 5, 9, 27, 31, 49, 71, 185, 207, 339, 457, 685, 1421, 1745, 2577, 3615, 5143, 6877, 13439, 15965, 23823, 31983, 45553, 59425, 83549, 139013, 173769, 244803, 330391, 452257, 597935, 810929, 1052559, 1692723, 2074321, 2890333, 3783821
(list; graph; listen)
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OFFSET
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1,3
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FORMULA
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G.f.: Sum(k >= 0; k*k! x^((k^2+k)/2) / Prod(1<=j<=k; 1-x^j)).
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MATHEMATICA
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Drop[ CoefficientList[ Series[ Sum[ k*k!*x^((k^2 + k)/2)/Product[1 - x^j, {j, 1, k}], {k, 1, 45}], {x, 0, 40}], x], 1] (from Robert G. Wilson v Sep 08 2004)
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CROSSREFS
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Cf. A001792, A015723, A032020.
Adjacent sequences: A097907 A097908 A097909 this_sequence A097911 A097912 A097913
Sequence in context: A047880 A058491 A058584 this_sequence A049122 A078560 A040021
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KEYWORD
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easy,nonn
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AUTHOR
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Vladeta Jovovic (vladeta(AT)Eunet.yu), Sep 04 2004
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com) and John W. Layman (layman(AT)math.vt.edu), Sep 08 2004
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