|
|
A202310
|
|
Number of (n+2) X 3 binary arrays avoiding patterns 001 and 100 in rows and columns.
|
|
1
|
|
|
108, 333, 1144, 4048, 14743, 54250, 201098, 747683, 2785178, 10383774, 38732585, 144511028, 539243500, 2012324661, 7509786472, 28026278000, 104594259855, 390348614698, 1456795959866, 5436826706395, 20290493971290, 75725115284622
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 6*a(n-1) -5*a(n-2) -22*a(n-3) +32*a(n-4) +16*a(n-5) -35*a(n-6) +2*a(n-7) +9*a(n-8) -2*a(n-9).
Empirical g.f.: x*(108 - 315*x - 314*x^2 + 1225*x^3 + 45*x^4 - 1184*x^5 + 213*x^6 + 290*x^7 - 72*x^8) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - 4*x + x^2)*(1 + x - x^2)*(1 - x - x^2)). - Colin Barker, Feb 14 2018
|
|
EXAMPLE
|
Some solutions for n=6:
..0..1..1....1..1..1....0..1..0....0..1..1....1..0..1....0..1..0....1..1..1
..1..1..1....1..1..0....1..1..1....1..1..0....0..1..0....1..1..1....1..1..0
..1..1..1....0..1..1....0..0..0....0..1..1....1..0..1....1..1..1....0..1..1
..0..1..1....1..1..1....1..1..1....1..1..1....1..1..1....0..0..0....1..0..1
..1..1..0....0..1..1....1..1..1....1..0..1....1..0..1....1..1..1....0..1..0
..1..0..1....1..0..1....0..1..1....1..1..1....0..1..0....1..1..1....1..1..1
..1..1..0....0..1..1....1..1..0....1..1..0....1..0..1....1..1..1....1..1..1
..0..1..1....1..0..1....1..1..1....0..1..1....1..1..1....1..0..1....1..1..0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|