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A051365 Number of 4-element families of an n-element set such that every 3 members of the family have a non-empty intersection. 0
0, 0, 0, 3, 275, 8475, 192385, 3831093, 71466675, 1285857975, 22632300245, 392522268633, 6734698919575, 114576024346875, 1935649374363705, 32505459713369373 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

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

1/4! (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)

CROSSREFS

Cf. A036239, A051180-A051185.

Sequence in context: A003761 A171358 A115477 * A003706 A068250 A096126

Adjacent sequences:  A051362 A051363 A051364 * A051366 A051367 A051368

KEYWORD

nonn

AUTHOR

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

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Last modified February 15 08:20 EST 2012. Contains 205729 sequences.