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A056823
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Counts members of A056808 by number of factors.
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1
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0, 0, 0, 1, 3, 9, 21, 49, 106, 226, 470, 968, 1971, 3995, 8057, 16208, 32537, 65239, 130687, 261654, 523661, 1047784, 2096150, 4193049, 8387033, 16775258, 33551996, 67105854, 134214010, 268430891, 536865308, 1073734982, 2147475299
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OFFSET
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0,5
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COMMENTS
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A056808 relates to least prime signatures (cf. A025487)
a(n) is the number of redundant partitions of n. [From Omar E. Pol, Jan 31 2009]
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LINKS
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Table of n, a(n) for n=0..32.
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FORMULA
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A011782(n) - A000041(n)
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EXAMPLE
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A011782 begins 1 1 2 4 8 16 32 64 128 256 ...; A000041 begins 1 1 2 3 5 7 11 15 22 30 ...; hence a(n) = 0 0 0 1 3 9 21 49 106 226 ... For n = 3 the factorizations are 8=2*2*2, 12=2*2*3, 18=2*3*3 and 30 =2*3*5.
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MAPLE
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seq(count(Composition(n))-count(Partition(n)), n=1..32); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Oct 16 2006
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CROSSREFS
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Cf. A000041, A011782, A025487 and A056808.
Sequence in context: A000714 A090984 A006813 * A105544 A119917 A111209
Adjacent sequences: A056820 A056821 A056822 * A056824 A056825 A056826
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KEYWORD
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easy,nonn
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AUTHOR
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Alford Arnold, Aug 29 2000
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EXTENSIONS
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More terms from James A. Sellers, Aug 31 2000
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STATUS
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approved
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