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A234116 Number of (n+1) X (2+1) 0..2 arrays with every 2 X 2 subblock having the absolute values of all six edge and diagonal differences no larger than 1. 1
145, 1361, 12593, 116801, 1082977, 10041953, 93113761, 863396401, 8005833073, 74233997105, 688333901137, 6382568345057, 59182293086657, 548767146042305, 5088437180610625, 47182476443409233, 437498981379983185 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 10*a(n-1) - 4*a(n-2) - 26*a(n-3) + 5*a(n-4).

Empirical g.f.: x*(145 - 89*x - 437*x^2 + 85*x^3) / (1 - 10*x + 4*x^2 + 26*x^3 - 5*x^4). - Colin Barker, Oct 12 2018

EXAMPLE

Some solutions for n=4:

..1..1..2....1..1..1....0..1..1....1..1..1....1..2..1....0..0..1....0..0..1

..2..1..2....1..1..2....1..0..1....2..1..0....2..2..2....0..1..0....0..0..1

..1..1..1....2..2..1....1..0..1....1..1..1....1..1..2....0..0..1....0..0..0

..2..2..1....1..1..2....1..0..0....2..1..2....0..1..2....1..1..1....0..0..1

..1..2..1....2..2..1....0..1..1....2..1..2....1..1..1....1..1..1....0..1..0

CROSSREFS

Column 2 of A234122.

Sequence in context: A297732 A296972 A269015 * A232151 A264284 A008377

Adjacent sequences:  A234113 A234114 A234115 * A234117 A234118 A234119

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 19 2013

STATUS

approved

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Last modified August 3 14:40 EDT 2021. Contains 346438 sequences. (Running on oeis4.)