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Search: id:A066187
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| A066187 |
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Sum of the second moments of all partitions of n. |
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+0
1
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| 1, 7, 23, 66, 145, 321, 600, 1137, 1964, 3379, 5463, 8888, 13714, 21206, 31737, 47319, 68727, 99718, 141488, 200383, 279097, 387302, 530286, 724113, 976949, 1314106, 1751079, 2325412, 3062942, 4022617
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OFFSET
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1,2
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COMMENT
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The first element of each partition is given weight 1.
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EXAMPLE
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a(3)=23 because the second moments of all partitions of 3 are {3}.{1},{2,1}.{1,4} and {1,1,1}.{1,4,9}, resulting in 3,6,14; summing to 23.
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MATHEMATICA
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Table[ Plus@@Map[ #.Range[ Length[ # ]]^2&, Partitions[ n ]], {n, 30} ]
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CROSSREFS
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Adjacent sequences: A066184 A066185 A066186 this_sequence A066188 A066189 A066190
Sequence in context: A104149 A001275 A003261 this_sequence A114246 A048457 A048458
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KEYWORD
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easy,nonn
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AUTHOR
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Wouter Meeussen (wouter.meeussen(AT)pandora.be), Dec 15 2001
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