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Search: id:A051364
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| A051364 |
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Number of 5-element families of an n-element set such that every 3 members of the family have a non-empty intersection. |
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+0
1
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| 0, 0, 0, 0, 225, 21571, 1174122, 51441824, 2038356243, 76714338477, 2804947403364, 100732231517698, 3572491367063421, 125474030774355263, 4371052010746528926, 151172238539268318372
(list; graph; listen)
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OFFSET
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0,5
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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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1/5! (32^n - 10*28^n + 30*26^n + 5*25^n - 80*24^n + 45*23^n + 105*22^n - 217*21^n + 205*20^n - 120*19^n + 45*18^n - 10*17^n - 9*16^n + 40*14^n - 60*13^n + 40*12^n - 10*11^n + 35*8^n - 35*7^n - 50*4^n + 50*3^n + 24*2^n - 24)
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CROSSREFS
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Cf. A036239, A051180-A051185.
Sequence in context: A164763 A164752 A151651 this_sequence A061051 A036428 A109688
Adjacent sequences: A051361 A051362 A051363 this_sequence A051365 A051366 A051367
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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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