A207183 Number of 4Xn 0..1 arrays avoiding 0 0 0 horizontally and 0 1 0 vertically.

12, 144, 1171, 11227, 105836, 981850, 9196215, 85977231, 803283624, 7509476422, 70190937945, 656058072353, 6132248125196, 57318047597584, 535750978547941, 5007668680211309, 46806669029193682, 437501879260273952

Offset

1,1

Comments

Row 4 of A207182

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +26*a(n-2) +217*a(n-3) +103*a(n-4) +85*a(n-5) -4044*a(n-6) +1053*a(n-7) -6517*a(n-8) +27058*a(n-9) -11158*a(n-10) +29024*a(n-11) -63148*a(n-12) +15300*a(n-13) -29296*a(n-14) +43157*a(n-15) +2016*a(n-16) +4274*a(n-17) -7152*a(n-18) -147*a(n-19) -45*a(n-20) +375*a(n-21)

Example

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

Crossrefs

Sequence in context: A207090 A189259 A189612 * A188987 A189697 A189059

Adjacent sequences: A207180 A207181 A207182 * A207184 A207185 A207186

Keyword

nonn

Author

R. H. Hardin, Feb 15 2012

Status

approved