A251368 Number of (n+1) X (3+1) 0..2 arrays with every 2 X 2 subblock summing to 1 2 3 4 5 6 or 7.

6113, 464393, 35257505, 2676962017, 203249994369, 15431888950873, 1171676222709377, 88960280954218353, 6754367316602393761, 512829741092571856681, 38936932361040303524065, 2956311969073264569680513

Offset: 1

Author

R. H. Hardin, Dec 01 2014

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 3 of A251373.

Formula

Empirical: a(n) = 66*a(n-1) + 746*a(n-2) + 660*a(n-3) - 6281*a(n-4) + 3690*a(n-5).

Empirical g.f.: x*(6113 + 60935*x + 47269*x^2 - 505071*x^3 + 298890*x^4) / (1 - 66*x - 746*x^2 - 660*x^3 + 6281*x^4 - 3690*x^5). - Colin Barker, Nov 29 2018