A227748 Number of nX3 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X4 binary array having determinant equal to one

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

R. H. Hardin, Table of n, a(n) for n = 1..210

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

Adjacent sequences: A227745 A227746 A227747 * A227749 A227750 A227751

Keyword

nonn

Author

R. H. Hardin Jul 25 2013

Status

approved