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A056049 Number of 6-antichain covers of a labeled n-set. 7
1, 1375, 751192, 187216960, 29650991279, 3554308158345, 355235190457414, 31360944940860370, 2536696962910365277, 192628889065040142715, 13964833124133659520116, 978098391719401853480580 (list; graph; refs; listen; history; text; internal format)
OFFSET
4,2
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.
LINKS
K. S. Brown, Dedekind's problem
Eric Weisstein's World of Mathematics, Antichain covers
FORMULA
a(n)=(1/6!)*(63^n - 30*47^n + 120*39^n + 60*35^n + 60*33^n - 12*32^n - 345*31^n - 720*29^n + 810*27^n + 120*26^n + 480*25^n + 360*24^n - 480*23^n - 720*22^n - 240*21^n - 540*20^n + 1380*19^n + 750*18^n + 60*17^n - 210*16^n - 1535*15^n - 1820*14^n + 2250*13^n + 1800*12^n - 2820*11^n + 300*10^n + 2040*9^n + 340*8^n - 1815*7^n + 510*6^n - 1350*5^n + 1350*4^n + 274*3^n - 548*2^n + 120).
MATHEMATICA
Table[(1 / 6!) (63^n - 30*47^n + 120*39^n + 60*35^n + 60 *33^n - 12*32^n - 345*31^n-720*29^n + 810*27^n + 120*26^n + 480*25^n + 360*24^n - 480*23^n - 720*22^n -240*21^n - 540*20^n + 1380*19^n + 750*18^n + 60*17^n - 210*16^n - 1535*15^n - 1820*14^n + 2250*13^n + 1800*12^n - 2820*11^n + 300*10^n + 2040*9^n + 340*8^n - 1815*7^n + 510*6^n - 1350*5^n + 1350*4^n + 274*3^n -548*2^n + 120), {n, 4, 20}] (* Vincenzo Librandi, Jun 17 2013 *)
CROSSREFS
Cf. A051114.
Sequence in context: A349235 A045131 A365868 * A206340 A056087 A122692
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Goran Kilibarda, Zoran Maksimovic, Jul 25 2000
STATUS
approved

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Last modified May 23 20:34 EDT 2024. Contains 372765 sequences. (Running on oeis4.)