A207950 Number of 4 X n 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 1 0 and 1 0 1 vertically.

10, 100, 370, 1369, 3478, 8836, 18330, 38025, 69420, 126736, 211820, 354025, 554540, 868624, 1294548, 1929321, 2764110, 3960100, 5494390, 7623121, 10298530, 13912900, 18377710, 24275329, 31453968, 40755456, 51933840, 66178225, 83107160

Offset

1,1

Comments

Row 4 of A207949.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) -14*a(n-3) -14*a(n-4) +42*a(n-5) +14*a(n-6) -70*a(n-7) +70*a(n-9) -14*a(n-10) -42*a(n-11) +14*a(n-12) +14*a(n-13) -6*a(n-14) -2*a(n-15) +a(n-16).

Example

Some solutions for n=4
..0..0..0..0....0..1..0..1....1..0..0..0....1..0..0..0....1..1..1..1
..1..1..1..0....0..1..0..1....1..0..0..0....0..1..0..0....1..1..1..1
..1..1..1..0....1..0..1..0....1..1..1..0....0..1..0..1....1..1..1..1
..1..1..0..1....1..0..1..0....1..1..1..1....1..1..1..1....1..1..1..0

Crossrefs

Cf. A207949.

Sequence in context: A207919 A208699 A207255 * A207859 A207809 A208283

Adjacent sequences: A207947 A207948 A207949 * A207951 A207952 A207953

Keyword

nonn

Author

R. H. Hardin, Feb 21 2012

Status

approved