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A186056
Number of (n+2)X4 binary arrays with each 3X3 subblock having a positive determinant
1
267, 1217, 5050, 18376, 77987, 319247, 1206478, 5004260, 20446314, 78510506, 321624753, 1312717589, 5093522285, 20696807255, 84349601913, 329882198919, 1333032278898, 5422775401978, 21339058001801, 85908053648127
OFFSET
1,1
COMMENTS
Column 2 of A186063
LINKS
FORMULA
Empirical: a(n)=86*a(n-3)+21*a(n-4)+24*a(n-5)-2063*a(n-6)-225*a(n-7)-146*a(n-8)+21658*a(n-9)-491*a(n-10)-2391*a(n-11)-114917*a(n-12)+12598*a(n-13)+28684*a(n-14)+319161*a(n-15)-45052*a(n-16)-111463*a(n-17)-457411*a(n-18)+54439*a(n-19)+170509*a(n-20)+348902*a(n-21)-15249*a(n-22)-102795*a(n-23)-166851*a(n-24)-5337*a(n-25)+30958*a(n-26)+46900*a(n-27)+2286*a(n-28)-5094*a(n-29)-6511*a(n-30)-509*a(n-31)+764*a(n-32)+350*a(n-33)+6*a(n-34)+32*a(n-35)
EXAMPLE
Some solutions for 6X4
..0..1..0..1....1..0..1..1....1..1..1..0....1..0..0..1....1..0..0..1
..1..1..1..0....0..1..0..0....1..0..1..1....1..1..1..1....0..1..1..1
..1..0..0..1....0..1..1..0....1..1..0..0....1..0..1..1....1..0..1..0
..0..1..0..1....1..0..1..1....0..1..1..0....1..0..0..1....1..0..0..1
..0..1..1..0....1..1..0..1....1..0..0..1....1..1..1..0....1..1..0..0
..1..0..0..1....0..1..0..0....1..1..0..1....0..0..1..1....1..0..1..1
CROSSREFS
Sequence in context: A306120 A232106 A049014 * A236740 A278382 A062037
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 11 2011
STATUS
approved