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A186477 Number of (n+1)X5 0..3 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors 1
1251, 2049, 4810, 16762, 25633, 67714, 101305, 286290, 456113, 1219034, 2037173, 5189546, 9017049, 22136029, 39734818, 94665157, 174517432, 405721297, 764487337, 1742099164, 3341954341, 7491958474, 14584990777, 32261305429 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 4 of A186482
LINKS
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>15
EXAMPLE
Some solutions for 3X5
..0..0..0..3..0....0..0..0..1..0....2..0..0..0..0....2..1..0..0..0
..2..0..0..0..3....3..0..0..0..1....2..0..0..0..0....3..0..1..0..0
..0..2..0..0..2....2..3..0..0..0....2..0..0..0..1....0..3..0..1..3
CROSSREFS
Sequence in context: A254287 A252958 A288354 * A045186 A344034 A344035
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 22 2011
STATUS
approved

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Last modified July 20 06:34 EDT 2024. Contains 374441 sequences. (Running on oeis4.)