|
|
A095670
|
|
Eighth column (m=7) of (1,4)-Pascal triangle A095666.
|
|
0
|
|
|
4, 29, 120, 372, 960, 2178, 4488, 8580, 15444, 26455, 43472, 68952, 106080, 158916, 232560, 333336, 468996, 648945, 884488, 1189100, 1578720, 2072070, 2691000, 3460860, 4410900, 5574699, 6990624, 8702320, 10759232, 13217160, 16138848
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
COMMENTS
|
If Y is a 4-subset of an n-set X then, for n>=10, a(n-10) is the number of 7-subsets of X having at most one element in common with Y. - Milan Janjic, Dec 08 2007
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (4-3*x)/(1-x)^8.
a(n) = 4*b(n)-3*b(n-1) =(n+28)*binomial(n+6, 6)/7, with b(n):=binomial(n+7, 7)= A000580(n+7, 7).
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|