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A186480 Number of (n+1)X8 0..3 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors 1
20079, 14492, 82632, 101305, 433513, 418177, 1849873, 1894849, 7687009, 8602033, 31645329, 39574001, 131802797, 181420169, 553069145, 820669641, 2331052105, 3678141757, 9868524241, 16371829777, 41936161201, 72480530737, 178779125389 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A186482

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n)=2*a(n-1)+2*a(n-2)-6*a(n-3)+6*a(n-4)-3*a(n-5) for n>18

EXAMPLE

Some solutions for 3X8

..0..0..0..0..1..0..0..0....2..0..1..0..1..0..2..0....1..0..2..0..0..0..3..3

..3..0..0..0..0..1..0..0....0..2..0..1..0..1..0..2....0..1..0..2..0..0..0..3

..2..3..0..0..0..0..1..0....3..0..2..0..1..0..1..0....3..0..1..0..2..0..0..0

CROSSREFS

Sequence in context: A251986 A251880 A186565 * A204864 A145535 A190474

Adjacent sequences:  A186477 A186478 A186479 * A186481 A186482 A186483

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 22 2011

STATUS

approved

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Last modified May 15 16:02 EDT 2021. Contains 343920 sequences. (Running on oeis4.)