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A227748
Number of nX3 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X4 binary array having determinant equal to one
1
7, 40, 210, 1122, 6002, 32114, 171759, 918746, 4914405, 26287020, 140609297, 752118530, 4023077949, 21519427103, 115107316893, 615708512376, 3293422046623, 17616499557546, 94230576122959, 504038923797692
OFFSET
1,1
COMMENTS
Column 3 of A227751
LINKS
FORMULA
Empirical: a(n) = a(n-1) +12*a(n-2) +44*a(n-3) +71*a(n-4) +78*a(n-5) +40*a(n-6) -7*a(n-7) -33*a(n-8) -14*a(n-9) +11*a(n-10) -a(n-11) -4*a(n-12) +a(n-13)
EXAMPLE
Some solutions for n=4
..1..1..0....0..1..1....0..0..0....1..0..1....0..0..1....0..0..0....1..0..1
..0..1..0....0..0..0....0..0..0....0..0..0....0..0..0....0..1..1....0..0..0
..1..0..1....1..0..0....0..1..0....1..0..0....0..0..1....0..0..0....0..1..0
..1..0..0....0..1..0....0..0..0....1..0..1....0..0..0....1..0..0....1..0..1
CROSSREFS
Sequence in context: A268402 A351529 A081039 * A349594 A083327 A026716
KEYWORD
nonn
AUTHOR
R. H. Hardin Jul 25 2013
STATUS
approved