A207804 Number of nX4 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 0 and 1 0 1 vertically

10, 100, 378, 1970, 9168, 44538, 212814, 1022652, 4904350, 23540322, 112961952, 542115042, 2601499810, 12484112380, 59908695042, 287491745166, 1379628582160, 6620628961338, 31771352156610, 152465531316540, 731656970494958

Offset

1,1

Comments

Column 4 of A207808

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +a(n-2) -8*a(n-3) +53*a(n-4) +166*a(n-5) +347*a(n-6) +208*a(n-7) -166*a(n-8) -780*a(n-9) -2484*a(n-10) -3678*a(n-11) -3721*a(n-12) -644*a(n-13) +1359*a(n-14) +1318*a(n-15) +536*a(n-16) -82*a(n-17) +446*a(n-18) -106*a(n-19) -85*a(n-20) -32*a(n-21) -47*a(n-22) +28*a(n-23) -9*a(n-24) +a(n-26)

Example

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

Crossrefs

Sequence in context: A208283 A208416 A208024 * A060522 A086115 A209652

Adjacent sequences: A207801 A207802 A207803 * A207805 A207806 A207807

Keyword

nonn

Author

R. H. Hardin Feb 20 2012

Status

approved