A237915 Number of (n+1)X(1+1) 0..3 arrays with the upper median plus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

256, 1584, 9892, 63476, 406468, 2591160, 16574240, 105734776, 676470380, 4314907116, 27605297244, 176086915376, 1126539110360, 7185841737072, 45972584759476, 293245625954804, 1876081040647348, 11966954890116312

Offset

1,1

Comments

Column 1 of A237921

Links

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

Formula

Empirical: a(n) = 9*a(n-2) +1028*a(n-4) +10373*a(n-6) +27367*a(n-8) -32996*a(n-10) -169776*a(n-12) -127168*a(n-14) +64512*a(n-16) +589824*a(n-18)

Example

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

Crossrefs

Sequence in context: A237677 A237672 A237921 * A238081 A238074 A251974

Adjacent sequences: A237912 A237913 A237914 * A237916 A237917 A237918

Keyword

nonn

Author

R. H. Hardin, Feb 15 2014

Status

approved