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A202455
Number of (n+2) X 4 binary arrays with consecutive windows of three bits considered as a binary number nondecreasing in every row and column.
1
729, 1194, 1876, 2835, 4137, 5854, 8064, 10851, 14305, 18522, 23604, 29659, 36801, 45150, 54832, 65979, 78729, 93226, 109620, 128067, 148729, 171774, 197376, 225715, 256977, 291354, 329044, 370251, 415185, 464062, 517104, 574539, 636601, 703530
OFFSET
1,1
COMMENTS
Column 2 of A202461.
LINKS
FORMULA
Empirical: a(n) = (1/4)*n^4 + (15/2)*n^3 + (229/4)*n^2 + 237*n + 427.
Conjectures from Colin Barker, May 31 2018: (Start)
G.f.: x*(729 - 2451*x + 3196*x^2 - 1895*x^3 + 427*x^4) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)
EXAMPLE
Some solutions for n=4:
..0..0..0..0....0..0..0..0....0..1..0..0....0..0..0..0....0..0..0..0
..0..1..1..1....0..0..0..0....0..1..0..0....0..0..0..0....0..0..1..0
..0..1..1..1....0..0..0..0....0..1..0..0....0..0..0..0....0..0..1..0
..1..1..1..1....0..1..0..1....0..1..1..0....0..0..0..0....0..1..1..0
..1..1..1..1....0..0..1..1....0..1..0..0....0..0..1..0....0..1..1..1
..0..1..1..1....0..0..1..1....1..1..1..1....0..0..0..1....1..1..1..1
CROSSREFS
Cf. A202461.
Sequence in context: A045791 A088035 A054259 * A046319 A119710 A043455
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 19 2011
STATUS
approved