A237967 Number of (n+1)X(1+1) 0..3 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

256, 1494, 7905, 40442, 208210, 1074202, 5540337, 28475040, 146747184, 755218808, 3893371264, 20027524168, 103232219796, 531114565248, 2737826075360, 14084875246240, 72603362037280, 373519603204256, 1925412625288848

Offset

1,1

Comments

Column 1 of A237974

Links

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

Formula

Empirical: a(n) = 488*a(n-4) +5140*a(n-6) +14624*a(n-8) +12288*a(n-10) for n>13

Example

Some solutions for n=4
..3..0....0..3....2..1....2..1....2..0....3..3....3..2....2..2....3..2....3..0
..2..3....1..3....1..0....0..3....3..2....3..2....3..2....3..1....0..1....0..0
..2..1....2..1....0..0....3..2....3..0....1..1....1..0....0..0....0..2....1..2
..1..0....1..1....2..1....1..2....2..0....0..0....0..3....3..2....0..0....3..1
..2..2....2..3....1..3....1..0....3..3....0..1....0..0....3..0....1..3....0..0

Crossrefs

Sequence in context: A237143 A333606 A237974 * A237142 A237135 A197709

Adjacent sequences: A237964 A237965 A237966 * A237968 A237969 A237970

Keyword

nonn

Author

R. H. Hardin, Feb 16 2014

Status

approved