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Search: id:A151897
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| A151897 |
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Number of subsets of {1, 2, ..., n} such that no member is a sum of distinct other members. |
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+0
1
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| 2, 4, 7, 13, 22, 37, 60, 100, 155, 249, 381, 591, 889, 1365, 2009, 3047, 4453, 6602, 9567, 14151, 20228, 29654, 42302, 61369, 87108, 126066, 177580, 256039, 360304, 515740, 724069, 1036860, 1448746, 2069526, 2893311, 4117725, 5749540, 8186555
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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a(4) = 13, including all subsets of {1, 2, 3, 4} except {1, 2, 3} (excluded
because 1+2 = 3), {1, 3, 4} (excluded because 1+3 = 4), and {1, 2, 3, 4} (excluded for both reasons.)
This sequence and A085489 first differ at n = 7. a(7) = 60, A085489(7) = 61. A085489(7)
includes {1, 2, 4, 7}, which is excluded from a(7) because 1+2+4 = 7.
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CROSSREFS
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Cf. A085489, A103580.
Sequence in context: A088111 A143823 A119983 this_sequence A085489 A101268 A128768
Adjacent sequences: A151894 A151895 A151896 this_sequence A151898 A151899 A151900
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KEYWORD
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nonn
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AUTHOR
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David Wasserman (dwasserm(AT)earthlink.net), Apr 16 2008
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