A207307 - OEIS

A207307

Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 0 vertically

8, 64, 200, 643, 1759, 4939, 14446, 41505, 118266, 339548, 975493, 2795633, 8015023, 22994104, 65948845, 189120690, 542403026, 1555646545, 4461518045, 12795484071, 36697414724, 105247642363, 301847990088, 865695191094, 2482800552095

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Row 4 of A207305

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +2*a(n-2) +8*a(n-3) +7*a(n-4) -2*a(n-5) -10*a(n-6) -10*a(n-7) -a(n-8) +3*a(n-9) +4*a(n-10) +a(n-11) -a(n-13) for n>14

EXAMPLE

Some solutions for n=4

..1..0..0..1....0..0..1..0....1..1..0..0....0..0..1..1....1..1..1..1

..0..1..1..0....1..0..0..1....1..1..0..0....1..0..0..1....1..1..1..1

..1..0..0..1....0..0..1..0....1..1..0..0....0..0..1..1....1..1..1..1

..1..1..1..1....1..0..0..1....1..1..0..0....0..0..1..1....1..1..1..1

CROSSREFS

Sequence in context: A207027 A207172 A207455 * A207113 A207393 A207940

Adjacent sequences: A207304 A207305 A207306 * A207308 A207309 A207310

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 16 2012

STATUS

approved