A239334 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it, modulo 4.

5, 31, 172, 926, 5078, 27861, 152260, 832207, 4550810, 24881731, 136029644, 743697760, 4065948624, 22229220072, 121530709245, 664428372582, 3632538661095, 19859679158791, 108576093277449, 593603153333233

Offset: 1

Author

R. H. Hardin, Mar 16 2014

Keywords

• nonn

Comments

Column 2 of A239340

Examples

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

Links

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

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)