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A186895
Number of (n+1)X3 binary arrays with every 2X2 subblock determinant equal to exactly one or two horizontal and vertical neighbor 2X2 subblock determinants
1
30, 148, 140, 406, 1246, 3106, 7240, 19040, 49004, 124974, 318420, 814714, 2080852, 5324036, 13622742, 34838372, 89070962, 227812618, 582742964, 1490551186, 3812248194, 9750367192, 24938804546, 63787545162, 163151712528, 417295494174
OFFSET
1,1
COMMENTS
Column 2 of A186902
LINKS
FORMULA
Empirical: a(n)=a(n-1)+a(n-2)+4*a(n-3)+9*a(n-4)+9*a(n-5)+a(n-6)-26*a(n-7)-50*a(n-8)-58*a(n-9)-32*a(n-10)-17*a(n-11)-a(n-12)+14*a(n-13)+61*a(n-14)+66*a(n-15)+50*a(n-16)+13*a(n-17) for n>19
EXAMPLE
Some solutions for 5X3
..1..1..0....1..0..1....1..0..1....0..0..1....0..0..1....0..1..0....0..0..0
..0..1..1....1..0..0....1..0..0....0..0..1....0..0..1....0..1..0....0..1..0
..0..0..1....1..0..1....1..1..0....1..1..1....0..1..1....0..1..1....1..1..0
..0..1..1....1..1..1....0..1..1....1..1..0....1..1..0....0..0..1....1..0..0
..0..1..0....0..1..0....0..1..1....0..1..1....0..0..0....0..0..0....1..0..0
CROSSREFS
Sequence in context: A124958 A126417 A135175 * A185480 A316459 A342483
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 28 2011
STATUS
approved