|
| |
|
|
A051180
|
|
Number of 3-element intersecting families of an n-element set.
|
|
18
| |
|
|
0, 0, 0, 13, 222, 2585, 25830, 238833, 2111382, 18142585, 152937510, 1271964353, 10476007542, 85662034185, 696700867590, 5643519669073, 45575393343702, 367206720319385, 2953481502692070, 23723872215168993, 190372457332919862
(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
| 1/3!(8^n-3*6^n+3*5^n-4*4^n+3*3^n+2*2^n-2)
|
|
|
MAPLE
| seq(1/3!*(8^n-3*6^n+3*5^n-4*4^n+3*3^n+2*2^n-2), n=0..40);
|
|
|
CROSSREFS
| Cf. A036239, A051181-A051185.
Sequence in context: A015253 A051621 A173427 * A143832 A140841 A062127
Adjacent sequences: A051177 A051178 A051179 * A051181 A051182 A051183
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| Vladeta Jovovic, Goran Kilibarda (vladeta(AT)eunet.rs)
|
|
|
EXTENSIONS
| More terms from Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Mar 25 2002
|
| |
|
|
