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A205065
Number of (n+1) X 2 0..1 arrays with the number of rightwards and downwards edge increases in each 2 X 2 subblock differing from the number in all its horizontal and vertical neighbors.
1
16, 40, 98, 238, 584, 1432, 3516, 8622, 21158, 51894, 127322, 312310, 766198, 1879520, 4610912, 11311058, 27748262, 68070236, 166988412, 409647388, 1004934200, 2465259322, 6047686542, 14835930358, 36394946602, 89282603930
OFFSET
1,1
COMMENTS
Column 1 of A205072.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-2) + 2*a(n-3) + 4*a(n-5) - 3*a(n-6) + 4*a(n-8) - 2*a(n-9) for n > 10.
Empirical g.f.: 2*x*(8 + 20*x + 9*x^2 + 3*x^3 + 7*x^4 - 9*x^5 + 4*x^6 + 11*x^7 - 4*x^8 + x^9) / (1 - 5*x^2 - 2*x^3 - 4*x^5 + 3*x^6 - 4*x^8 + 2*x^9). - Colin Barker, Jun 10 2018
EXAMPLE
Some solutions for n=4:
1 0 0 1 0 1 1 1 1 1 0 0 1 0 0 0 1 1 0 0
0 1 0 0 1 1 1 1 0 1 1 0 0 0 0 1 1 1 0 1
0 0 1 1 0 1 0 1 0 1 0 1 0 1 0 0 0 1 0 0
0 1 1 1 0 1 0 1 0 0 0 0 0 0 0 1 1 1 0 0
0 0 0 1 0 0 0 0 1 1 1 1 0 1 0 0 1 1 0 1
CROSSREFS
Cf. A205072.
Sequence in context: A184030 A350284 A182461 * A368078 A185790 A185761
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 21 2012
STATUS
approved