A203177 Number of nX4 0..2 arrays with every 1 immediately preceded by 0 to the left or above, no 0 immediately preceded by a 0, and every 2 immediately preceded by 0 1 to the left or above

2, 4, 17, 59, 205, 724, 2466, 8948, 30945, 108083, 382615, 1333850, 4692643, 16441939, 57654309, 202490869, 709321155, 2489832932, 8732839148, 30624223891, 107449317301, 376820699674, 1321873641658, 4636665217896, 16263018992261

Offset

1,1

Comments

Column 4 of A203181

Links

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

Formula

Empirical: a(n) = 5*a(n-2) +34*a(n-3) +13*a(n-4) -38*a(n-5) -419*a(n-6) -124*a(n-7) +145*a(n-8) +2520*a(n-9) +37*a(n-10) -584*a(n-11) -6715*a(n-12) +1170*a(n-13) +55*a(n-14) +6304*a(n-15) +476*a(n-16) -78*a(n-17) -480*a(n-19)

Example

Some solutions for n=5
..0..1..2..0....0..1..2..0....0..1..2..0....0..1..2..0....0..1..0..1
..1..0..1..1....1..0..1..1....1..0..1..2....1..0..1..1....1..0..1..0
..0..1..0..1....0..1..2..0....0..1..2..0....0..1..0..1....0..1..0..1
..1..2..1..0....1..2..0..1....1..0..1..1....1..2..1..0....1..0..1..0
..0..1..0..1....0..1..1..2....0..1..2..0....2..0..2..1....2..1..2..1

Crossrefs

Sequence in context: A270359 A276557 A266868 * A096122 A014522 A020035

Adjacent sequences: A203174 A203175 A203176 * A203178 A203179 A203180

Keyword

nonn

Author

R. H. Hardin Dec 30 2011

Status

approved