A239399 Number of n X 2 0..3 arrays with no element equal to one plus the sum of elements to its left or two plus the sum of elements above it, modulo 4.

4, 23, 129, 698, 3805, 20818, 113774, 621754, 3399032, 18582965, 101593258, 555419633, 3036563927, 16601366841, 90762262155, 496211843813, 2712870511114, 14831702705726, 81087325012785, 443317575022163, 2423689199017701, 13250702601112477, 72443743963082659, 396061718589309511

Offset: 1

Author

R. H. Hardin, Mar 17 2014

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 2 of A239405.

Formula

Empirical: a(n) = 9*a(n-1) -28*a(n-2) +74*a(n-3) -181*a(n-4) +236*a(n-5) -261*a(n-6) +234*a(n-7) +200*a(n-8) -279*a(n-9) +104*a(n-10) -268*a(n-11) -36*a(n-12) +156*a(n-13) +104*a(n-14) -32*a(n-15) -16*a(n-16).