A234117 Number of (n+1) X (3+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.

673, 12593, 231713, 4279065, 79003521, 1458813409, 26937444801, 497411686793, 9184935953377, 169604155276817, 3131820756402657, 57830550281200505, 1067868451774107585, 19718695887361293761, 364115043587212161409

Offset

1,1

Links

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

Formula

Empirical: a(n) = 20*a(n-1) - 10*a(n-2) - 324*a(n-3) - 277*a(n-4) + 144*a(n-5).

Empirical g.f.: x*(673 - 867*x - 13417*x^2 - 11213*x^3 + 5904*x^4) / (1 - 20*x + 10*x^2 + 324*x^3 + 277*x^4 - 144*x^5). - Colin Barker, Oct 12 2018

Example

Some solutions for n=2:
..2..2..2..1....1..1..1..0....1..2..2..1....1..1..1..2....2..1..1..2
..2..1..1..1....0..0..0..0....1..1..1..2....0..1..2..1....2..2..1..1
..1..1..2..2....0..0..1..1....1..2..2..2....1..1..2..2....1..1..1..1

Crossrefs

Column 3 of A234122.

Sequence in context: A297123 A335254 A160209 * A171266 A267818 A158392

Adjacent sequences: A234114 A234115 A234116 * A234118 A234119 A234120

Keyword

nonn

Author

R. H. Hardin, Dec 19 2013

Status

approved