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A203361
Number of nX7 binary arrays with every 1 immediately preceded by 0 to the left or above
1
21, 1640, 89610, 5390325, 314688054, 18550312526, 1089970014327, 64114204398028, 3769915844080995, 221699388876599524, 13037021233036033635, 766652822812020772883, 45083423150083817466414, 2651159090798112000786121
OFFSET
1,1
COMMENTS
Column 7 of A203362
LINKS
FORMULA
Empirical: a(n) = 21*a(n-1) +1743*a(n-2) +25515*a(n-3) +156938*a(n-4) +213951*a(n-5) -1636533*a(n-6) -3128592*a(n-7) +23316551*a(n-8) +17066544*a(n-9) -199519590*a(n-10) +291472395*a(n-11) -22194350*a(n-12) -173766021*a(n-13) +129035841*a(n-14) -33578772*a(n-15) -2885164*a(n-16) +4086456*a(n-17) -689631*a(n-18) -24273*a(n-19) +4320*a(n-20) for n>21
EXAMPLE
Some solutions for n=3
..0..1..0..0..1..0..0....0..0..0..0..0..1..0....0..0..1..0..1..0..1
..0..0..1..0..0..1..1....0..1..0..0..0..1..1....0..0..1..0..1..0..1
..0..1..0..1..0..1..0....1..0..1..1..0..1..0....1..1..0..1..0..0..1
CROSSREFS
Sequence in context: A081786 A295414 A202800 * A192843 A130039 A221033
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 31 2011
STATUS
approved