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A202456
Number of (n+2) X 5 binary arrays with consecutive windows of three bits considered as a binary number nondecreasing in every row and column.
1
1000, 1876, 3362, 5735, 9338, 14586, 21972, 32073, 45556, 63184, 85822, 114443, 150134, 194102, 247680, 312333, 389664, 481420, 589498, 715951, 862994, 1033010, 1228556, 1452369, 1707372, 1996680, 2323606, 2691667, 3104590, 3566318, 4081016
OFFSET
1,1
COMMENTS
Column 3 of A202461.
LINKS
FORMULA
Empirical: a(n) = (1/20)*n^5 + 2*n^4 + (275/12)*n^3 + 113*n^2 + (10351/30)*n + 517.
Conjectures from Colin Barker, May 31 2018: (Start)
G.f.: x*(1000 - 4124*x + 7106*x^2 - 6297*x^3 + 2838*x^4 - 517*x^5) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)
EXAMPLE
Some solutions for n=4:
..0..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..1..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..1....0..0..0..0..0
..0..0..0..0..1....0..1..1..1..1....0..0..1..1..1....0..0..1..0..1
..0..0..1..0..0....1..1..1..1..1....0..0..1..0..1....0..0..0..1..1
..0..0..0..0..0....0..1..1..1..1....0..0..0..0..1....0..1..1..1..1
CROSSREFS
Cf. A202461.
Sequence in context: A004266 A004267 A319441 * A168650 A043491 A100988
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 19 2011
STATUS
approved