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A178689
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Partial sums of A122836 (number of topologies on n labeled elements in which at least one element belongs to some pair of noncomparable members of the topology).
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0
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0, 0, 0, 10, 253, 6384, 208887, 9673189, 651633791, 63901292323, 9040801794022, 1825884406581355, 521181413335003984, 208402574279716434454, 115825454535371969786250, 88852094572776191675804592
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OFFSET
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0,4
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COMMENTS
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All listed (the first 16) values are nonprimes. In the underlying sequence, only A122836(5) = 6131 is prime of the listed values.
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LINKS
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FORMULA
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EXAMPLE
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a(4) = 0 + 0 + 0 + 10 + 243 = 253 = 11 * 23.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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