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Search: id:A051365
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| A051365 |
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Number of 4-element families of an n-element set such that every 3 members of the family have a non-empty intersection. |
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1
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| 0, 0, 0, 3, 275, 8475, 192385, 3831093, 71466675, 1285857975, 22632300245, 392522268633, 6734698919575, 114576024346875, 1935649374363705, 32505459713369373
(list; graph; listen)
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OFFSET
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0,4
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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! (16^n-4*14^n+6*13^n-4*12^n+11^n-6*8^n+6*7^n+11*4^n-11*3^n-6*2^n+6)
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CROSSREFS
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Cf. A036239, A051180-A051185.
Sequence in context: A003761 A105318 A115477 this_sequence A003706 A068250 A096126
Adjacent sequences: A051362 A051363 A051364 this_sequence A051366 A051367 A051368
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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.rs)
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