|
|
A202446
|
|
Number of (n+2) X 9 binary arrays avoiding patterns 001 and 110 in rows, columns and nw-to-se diagonals.
|
|
1
|
|
|
888, 1568, 3652, 7238, 14338, 25576, 45156, 74150, 120170, 184864, 280724, 410102, 592098, 829896, 1151188, 1560118, 2095210, 2761696, 3611428, 4650854, 5947906, 7510376, 9425284, 11701894, 14449578, 17679200, 21526004, 26002582, 31273826
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 3*a(n-1) +a(n-2) -11*a(n-3) +6*a(n-4) +14*a(n-5) -14*a(n-6) -6*a(n-7) +11*a(n-8) -a(n-9) -3*a(n-10) +a(n-11) for n>12.
Empirical g.f.: 2*x*(444 - 548*x - 970*x^2 + 2241*x^3 + 446*x^4 - 3172*x^5 + 1138*x^6 + 1774*x^7 - 1346*x^8 - 192*x^9 + 416*x^10 - 103*x^11) / ((1 - x)^7*(1 + x)^4). - Colin Barker, May 31 2018
|
|
EXAMPLE
|
Some solutions for n=4:
..1..1..1..1..1..1..1..1..1....1..0..1..1..1..1..1..1..1
..1..0..1..0..0..0..0..0..0....1..0..1..0..0..0..0..0..0
..1..1..1..1..1..1..1..1..1....1..0..1..1..1..1..1..1..1
..1..0..1..0..1..0..0..0..0....1..0..1..0..1..0..1..0..1
..1..0..1..1..1..1..1..1..1....1..0..1..1..1..1..1..1..1
..1..0..1..1..1..1..1..1..1....1..0..1..0..1..1..1..1..1
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|