A209459 Number of nX2 0..6 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..6 introduced in row major order.

2, 6, 57, 700, 10676, 192994, 3966581, 89157292, 2122477292, 52308803176, 1315354516436, 33456562887760, 856485703088336, 22005434702222368, 566526069249475088, 14601678389694957760, 376583948372941600448

Offset: 1

Author

R. H. Hardin Mar 09 2012

Keywords

• nonn

Comments

Column 2 of A209465

Examples

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

Links

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

Formula

Empirical: a(n) = 44*a(n-1) -456*a(n-2) -1360*a(n-3) +25892*a(n-4) +16752*a(n-5) -259776*a(n-6) -406080*a(n-7) -129600*a(n-8) for n>9