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A051366 Number of 6-element families of an n-element set such that every 4 members of the family have a non-empty intersection. 0
0, 0, 0, 0, 112, 39761, 5318420, 506289623, 41378309308, 3133123494417, 227657567966500, 16152548751321851, 1129224692910819164, 78169242144478858373, 5373159786842137703140, 367368738925063893430959 (list; graph; refs; listen; history; internal format)
OFFSET

0,5

REFERENCES

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).

FORMULA

1/6! (64^n - 15*60^n + 60*58^n + 25*57^n - 240*56^n + 45*55^n + 705*54^n - 987*53^n - 351*52^n + 3040*51^n - 5445*50^n + 6105*49^n - 4939*48^n + 2997*47^n - 1365*46^n + 455*45^n - 105*44^n + 15*43^n - 42^n - 15*32^n + 75*30^n - 150*29^n + 150*28^n - 75*27^n + 15*26^n + 85*16^n - 85*15^n - 225*8^n + 225*7^n + 274*4^n - 274*3^n - 120*2^n + 120)

CROSSREFS

Cf. A036239, A051180-A051185.

Sequence in context: A049217 A206310 A063409 * A051363 A184898 A180039

Adjacent sequences:  A051363 A051364 A051365 * A051367 A051368 A051369

KEYWORD

nonn

AUTHOR

Vladeta Jovovic, Goran Kilibarda (vladeta(AT)eunet.rs)

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Last modified February 17 00:09 EST 2012. Contains 205978 sequences.