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A218836 Unmatched value maps: number of nX2 binary arrays indicating the locations of corresponding elements not equal to any horizontal or antidiagonal neighbor in a random 0..1 nX2 array 8
2, 7, 21, 65, 200, 616, 1897, 5842, 17991, 55405, 170625, 525456, 1618192, 4983377, 15346786, 47261895, 145547525, 448227521, 1380359512, 4250949112, 13091204281, 40315615410, 124155792775, 382349636061, 1177482265857, 3626169232672 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A218842

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 2*a(n-1) +3*a(n-2) +a(n-3)

G.f.: Q(0)/(2*x) -1/x , where Q(k) = 1 + 1/(1- x*(4*k+2 +3*x+x^2)/(x*(4*k+4 +3*x+x^2) + 1/Q(k+1))); (continued fraction). - Sergei N. Gladkovskii, Oct 04 2013

EXAMPLE

Some solutions for n=3

..1..1....1..1....0..0....1..0....0..0....1..0....0..0....1..1....0..0....1..0

..1..1....1..1....0..1....0..1....0..0....0..0....0..0....0..0....0..1....0..0

..1..1....0..0....0..0....1..1....0..1....1..1....1..1....1..1....1..1....0..1

CROSSREFS

Sequence in context: A106271 A027990 A037520 * A331722 A052911 A126133

Adjacent sequences:  A218833 A218834 A218835 * A218837 A218838 A218839

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 07 2012

STATUS

approved

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Last modified February 20 19:02 EST 2020. Contains 332082 sequences. (Running on oeis4.)