A234753 Number of (n+1) X (1+1) 0..3 arrays with 2 X 2 edge jumps all no more than +1 in one of the clockwise or counterclockwise directions or both.

110, 1014, 8968, 80010, 712722, 6350732, 56585338, 504183278, 4492335124, 40027273406, 356648038986, 3177778909824, 28314409931414, 252284955262302, 2247890695972232, 20028988949649010, 178460811756944538

Offset: 1

Author

R. H. Hardin, Dec 30 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 1 of A234760.

Formula

Empirical: a(n) = 8*a(n-1) + 10*a(n-2) - 16*a(n-3) - 8*a(n-4) + 4*a(n-5) + a(n-6).

Empirical g.f.: 2*x*(55 + 67*x - 122*x^2 - 57*x^3 + 33*x^4 + 8*x^5) / (1 - 8*x - 10*x^2 + 16*x^3 + 8*x^4 - 4*x^5 - x^6). - Colin Barker, Oct 16 2018