|
|
A202459
|
|
Number of (n+2) X 8 binary arrays with consecutive windows of three bits considered as a binary number nondecreasing in every row and column.
|
|
1
|
|
|
2197, 5854, 14586, 33468, 71088, 141192, 264822, 473031, 810265, 1338508, 2142292, 3334680, 5064336, 7523802, 10959108, 15680847, 22076853, 30626626, 41917654, 56663788, 75725832, 100134516, 131116026, 170120271, 218852073, 279305472
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = (1/6720)*n^8 + (19/1680)*n^7 + (431/1440)*n^6 + (193/48)*n^5 + (90001/2880)*n^4 + (5873/40)*n^3 + (2076229/5040)*n^2 + (10915/14)*n + 823.
G.f.: x*(2197 - 13919*x + 40992*x^2 - 71610*x^3 + 80058*x^4 - 58194*x^5 + 26730*x^6 - 7071*x^7 + 823*x^8) / (1 - x)^9.
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9.
(End)
|
|
EXAMPLE
|
Some solutions for n=4:
..0..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0
..0..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..1
..0..0..0..0..0..1..1..1....0..0..0..0..0..1..0..0....0..0..0..0..0..1..1..1
..0..0..0..0..0..1..1..1....0..0..0..0..0..1..1..0....0..0..0..0..1..1..1..1
..0..1..1..1..1..1..1..1....0..0..0..0..1..1..1..1....0..0..1..1..1..1..1..1
..0..0..0..0..1..1..1..1....0..0..0..0..0..1..1..1....0..0..0..0..0..1..1..1
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|