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.

80, 380, 1776, 8336, 39084, 183304, 859628, 4031428, 18906220, 88664800, 415812536, 1950042036, 9145139904, 42888093244, 201132903028, 943255846788, 4423600410160, 20745421993920, 97290101680796, 456262778740936

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