|
|
A228479
|
|
Number of n X 5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or antidiagonally.
|
|
1
|
|
|
5, 19, 127, 728, 4354, 25699, 152373, 902042, 5342712, 31639786, 187379548, 1109702480, 6571916787, 38920392611, 230495519461, 1365047364511, 8084124028133, 47876038862427, 283532896714060, 1679146925634733
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Same recurrences as A228285 except in addition this smaller one for this column.
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 3*a(n-1) + 15*a(n-2) + 16*a(n-3) - 11*a(n-4) - 20*a(n-5) + 19*a(n-6) - 8*a(n-7) + a(n-9).
Empirical g.f.: x*(5 + 4*x - 5*x^2 - 18*x^3 + 16*x^4 - 6*x^5 + x^7) / (1 - 3*x - 15*x^2 - 16*x^3 + 11*x^4 + 20*x^5 - 19*x^6 + 8*x^7 - x^9). - Colin Barker, Sep 11 2018
|
|
EXAMPLE
|
Some solutions for n=4:
..1..0..1..0..0....1..0..0..0..0....1..0..0..0..0....1..0..1..0..0
..0..0..0..1..0....0..0..0..0..1....0..0..0..0..0....0..0..0..1..0
..1..0..0..0..1....1..0..0..0..0....1..0..0..0..0....1..0..0..0..0
..0..0..1..0..0....0..0..0..0..0....0..0..0..1..0....0..1..0..0..1
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|