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A186896 Number of (n+1)X4 binary arrays with every 2X2 subblock determinant equal to exactly one or two horizontal and vertical neighbor 2X2 subblock determinants 1
76, 140, 444, 1692, 3948, 13894, 35270, 122820, 328174, 1091770, 2989514, 9789230, 27386704, 88043136, 249821778, 792963658, 2277817920, 7153114096, 20739269674, 64581466696, 188672537578, 583564854384, 1715136004208, 5276315756596 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A186902
LINKS
FORMULA
Empirical: a(n)=8*a(n-2)+4*a(n-3)+10*a(n-4)-3*a(n-5)-73*a(n-6)-106*a(n-7)-22*a(n-8)+143*a(n-9)+154*a(n-10)+94*a(n-11)-115*a(n-12)-74*a(n-13)+33*a(n-14)+120*a(n-15)-30*a(n-16)-30*a(n-17)-8*a(n-18)+22*a(n-19)-12*a(n-20)-2*a(n-21)-4*a(n-22)+4*a(n-23) for n>29
EXAMPLE
Some solutions for 3X4
..1..1..1..0....1..1..0..0....0..0..0..0....0..0..1..1....0..0..1..1
..1..1..1..0....0..1..1..1....0..0..1..1....0..0..1..1....0..1..1..0
..0..0..1..1....0..0..0..0....0..1..1..0....0..1..1..0....0..0..0..0
CROSSREFS
Sequence in context: A092890 A261705 A248532 * A202173 A004924 A004944
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 28 2011
STATUS
approved

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Last modified February 29 19:20 EST 2024. Contains 370428 sequences. (Running on oeis4.)