A234124 Number of (n+1) X (1+1) 0..6 arrays with every 2 X 2 subblock having the absolute values of all six edge and diagonal differences no larger than 1.

91, 469, 2413, 12457, 64441, 333883, 1731979, 8992639, 46723771, 242899381, 1263281581, 6572316673, 34201861129, 178020202699, 926739961723, 4825035300439, 25123800838123, 130828761714565, 681313452720301

Offset

1,1

Links

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

Formula

Empirical: a(n) = 10*a(n-1) - 24*a(n-2) - 18*a(n-3) + 57*a(n-4) + 54*a(n-5) + 12*a(n-6).

Empirical g.f.: x*(91 - 441*x - 93*x^2 + 1221*x^3 + 1038*x^4 + 228*x^5) / (1 - 10*x + 24*x^2 + 18*x^3 - 57*x^4 - 54*x^5 - 12*x^6). - Colin Barker, Oct 12 2018

Example

Some solutions for n=5:
..3..3....4..5....1..0....1..0....2..2....5..5....6..5....1..1....2..3....3..2
..3..2....4..5....1..0....1..1....2..3....5..4....5..5....1..1....3..2....2..3
..3..3....4..4....0..0....2..2....3..3....5..4....4..4....2..2....3..2....2..2
..2..2....5..5....0..1....2..3....4..4....4..5....4..3....1..2....3..2....1..2
..2..3....5..4....0..1....3..3....3..3....4..4....4..4....2..2....3..2....2..2
..2..3....4..5....1..1....3..4....4..4....4..3....4..3....3..2....3..2....1..1

Crossrefs

Column 1 of A234131.

Sequence in context: A273799 A063137 A234131 * A373526 A373521 A180942

Adjacent sequences: A234121 A234122 A234123 * A234125 A234126 A234127

Keyword

nonn

Author

R. H. Hardin, Dec 19 2013

Status

approved