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A056052
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Number of 7-antichain covers of a labeled n-set.
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5
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490, 1305330, 1076513148, 474700998300, 143480504528862, 33962870686689270, 6808412143396065136, 1214116433267798496480, 198951942958529631990834, 30633642863234275154265690, 4502737302793395778228384164
(list; graph; refs; listen; history; internal format)
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OFFSET
| 5,1
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REFERENCES
| V. Jovovic and 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)
V. Jovovic, G. Kilibarda, On enumeration of the class of all monotone Boolean functions, in preparation.
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LINKS
| K. S. Brown, Dedekind's problem
Eric Weisstein's World of Mathematics, Antichain covers"
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FORMULA
| a(n)=(1/7!)*(127^n - 42*95^n + 210*79^n + 140*71^n + 210*67^n - 84*65^n + 14*64^n - 819*63^n - 2520*59^n + 2730*55^n + 840*53^n + 840*51^n - 420*50^n + 2940*49^n + 630*47^n - 5040*45^n + 840*44^n - 1260*43^n + 1680*42^n - 9660*41^n + 1260*40^n + 3360*39^n - 7560*38^n + 11130*37^n + 5880*36^n + 9240*35^n + 2982*34^n - 6300*33^n - 8652*32^n - 9905*31^n - 8400*30^n - 8540*29^n + 13860*28^n + 14490*27^n - 5040*26^n + 10500*25^n + 10080*24^n - 8120*23^n - 15050*22^n - 5040*21^n - 11340*20^n + 20580*19^n + 15750*18^n - 1540*17^n - 5810*16^n - 16485*15^n - 21420*14^n + 26250*13^n + 21000*12^n - 29820*11^n + 3500*10^n + 17640*9^n + 2940*8^n - 16016*7^n + 4410*6^n - 9744*5^n + 9744*4^n + 1764*3^n - 3528*2^n + 720).
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CROSSREFS
| Cf. A051115.
Sequence in context: A068751 A172951 A056936 * A051115 A060975 A180457
Adjacent sequences: A056049 A056050 A056051 * A056053 A056054 A056055
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KEYWORD
| nonn
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AUTHOR
| Vladeta Jovovic, Goran Kilibarda, Zoran Maksimovic (vladeta(AT)eunet.rs), Jul 25 2000
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