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Search: id:A097986
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| A097986 |
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Number of partitions of n into distinct parts, each of which has a part which divides every part in the partition. |
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+0
3
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| 1, 1, 2, 2, 2, 4, 3, 5, 5, 7, 6, 12, 9, 13, 15, 20, 18, 28, 26, 37, 39, 47, 49, 71, 68, 85, 94, 117, 120, 159, 160, 201, 216, 257, 277, 348, 357, 430, 470, 562, 592, 720, 758, 901, 981, 1134, 1220, 1457, 1542, 1798, 1952, 2250, 2419, 2819, 3023, 3482, 3773, 4291
(list; graph; listen)
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OFFSET
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1,3
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FORMULA
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a(n) = Sum_{d|n} A025147(d-1). G.f.: Sum(x^k*Product(1+x^(k*i), i=2..infinity), k=1..infinity).
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MATHEMATICA
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Take[ CoefficientList[ Expand[ Sum[x^k*Product[1 + x^(k*i), {i, 2, 62}], {k, 62}]], x], {2, 60}] (from Robert G. Wilson v Nov 01 2004)
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CROSSREFS
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Cf. A083710.
Sequence in context: A031437 A138241 A029145 this_sequence A155837 A096445 A125915
Adjacent sequences: A097983 A097984 A097985 this_sequence A097987 A097988 A097989
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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.rs), Oct 23 2004
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 01 2004
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