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Search: id:A052391
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| A052391 |
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Number of 4-element intersecting families (of distinct sets) whose union is an n-element set. |
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+0
1
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| 0, 0, 4, 349, 9985, 213230, 4000444, 69940479, 1170549895, 19024433560, 302846958634, 4748624978009, 73628721516805, 1132119741733890, 17298702716660824, 263082403948681939, 3986935934969727715
(list; graph; listen)
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OFFSET
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1,3
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REFERENCES
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V. Jovovic, G. Kilibarda, On the number of Boolean functions in the Post classes F^{mu}_8, Diskretnaya Matematika, 11 (1999), no. 4, 127-138 (translated in Discrete Mathematics and Applications, 9, (1999), no. 6).
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FORMULA
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1/4!*(15^n - 6*11^n + 12*9^n - 8^n - 22*7^n + 15*6^n + 12*5^n - 17*4^n + 17*3^n - 11*2^n - 6)
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CROSSREFS
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Cf. A051181, A053152, A053153.
Sequence in context: A098654 A069884 A074844 this_sequence A051955 A109760 A051181
Adjacent sequences: A052388 A052389 A052390 this_sequence A052392 A052393 A052394
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KEYWORD
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nonn
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AUTHOR
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Vladeta Jovovic, Goran Kilibarda (vladeta(AT)Eunet.yu), Mar 11 2000
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