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A227751
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T(n,k)=Number of nXk 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(k+1) binary array having determinant equal to one
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6
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2, 4, 4, 7, 13, 7, 13, 40, 40, 13, 24, 129, 210, 129, 24, 44, 409, 1122, 1122, 409, 44, 81, 1300, 6002, 10092, 6002, 1300, 81, 149, 4137, 32114, 90881, 90881, 32114, 4137, 149, 274, 13152, 171759, 817897, 1378923, 817897, 171759, 13152, 274, 504, 41825
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OFFSET
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1,1
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COMMENTS
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Table starts
...2.....4.......7........13..........24............44...............81
...4....13......40.......129.........409..........1300.............4137
...7....40.....210......1122........6002.........32114...........171759
..13...129....1122.....10092.......90881........817897..........7363367
..24...409....6002.....90881.....1378923......20935625........317839952
..44..1300...32114....817897....20935625.....536234494......13732639679
..81..4137..171759...7363367...317839952...13732639679.....593219255593
.149.13152..918746..66282981..4824746883..351648537470...25621579279915
.274.41825.4914405.596664236.73241810146.9004763615933.1106648265092084
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LINKS
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FORMULA
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Empirical for column k:
k=1: a(n) = a(n-1) +a(n-2) +a(n-3)
k=2: a(n) = a(n-1) +4*a(n-2) +8*a(n-3) +4*a(n-4) +a(n-5) -a(n-6)
k=3: [order 13]
k=4: [order 32]
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EXAMPLE
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Some solutions for n=4 k=4
..1..0..0..1....0..1..1..0....1..0..1..0....0..0..0..0....1..0..1..1
..0..0..0..0....0..0..0..1....1..0..1..0....0..0..0..1....0..0..0..1
..0..0..0..0....1..0..0..1....0..1..0..0....0..1..0..0....1..0..0..0
..0..0..1..1....1..0..1..0....0..1..1..0....1..0..1..1....1..0..0..0
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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