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A227751 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 6
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 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..219

FORMULA

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]

EXAMPLE

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

CROSSREFS

Column 1 is A000073(n+3)

Sequence in context: A224158 A224409 A226870 * A268995 A205744 A237859

Adjacent sequences: A227748 A227749 A227750 * A227752 A227753 A227754

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Jul 25 2013

STATUS

approved

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Last modified December 5 02:30 EST 2022. Contains 358572 sequences. (Running on oeis4.)