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A233951 Number of (n+1) X (1+1) 0..5 arrays with every 2 X 2 subblock having the sum of the squares of the edge differences equal to 10, and no two adjacent values equal. 1
80, 380, 1776, 8336, 39084, 183304, 859628, 4031428, 18906220, 88664800, 415812536, 1950042036, 9145139904, 42888093244, 201132903028, 943255846788, 4423600410160, 20745421993920, 97290101680796, 456262778740936 (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) = 4*a(n-1) + 5*a(n-2) - 7*a(n-3) - 6*a(n-4).

Empirical g.f.: 4*x*(4 + 3*x)*(5 - 9*x^2) / (1 - 4*x - 5*x^2 + 7*x^3 + 6*x^4). - Colin Barker, Oct 12 2018

EXAMPLE

Some solutions for n=5:

..0..1....5..4....1..3....5..4....4..5....4..2....3..2....2..1....1..0....2..1

..2..3....4..2....0..1....3..5....2..4....3..1....5..3....1..3....3..2....4..2

..3..1....2..3....2..0....4..3....4..3....2..0....3..2....3..4....5..3....5..3

..4..3....4..5....3..2....3..1....2..4....3..2....2..0....1..3....4..2....4..5

..2..1....2..3....2..4....4..3....1..2....1..3....3..2....0..1....2..3....2..4

..1..3....3..5....4..3....2..4....2..0....3..2....5..3....2..0....4..5....1..3

CROSSREFS

Column 1 of A233958.

Sequence in context: A204475 A157953 A233958 * A045666 A045657 A273292

Adjacent sequences:  A233948 A233949 A233950 * A233952 A233953 A233954

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 18 2013

STATUS

approved

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Last modified October 15 21:38 EDT 2021. Contains 348034 sequences. (Running on oeis4.)