A234754 Number of (n+1)X(2+1) 0..3 arrays with 2X2 edge jumps all no more than +1 in one of the clockwise or counterclockwise directions or both.

1014, 26642, 646036, 15939010, 392044622, 9648827736, 237446135146, 5843394219306, 143801532689336, 3538850266550630, 87088497253969902, 2143183802626938104, 52742175287648016058, 1297946099417129620238

Offset: 1

Author

R. H. Hardin, Dec 30 2013

Keywords

• nonn

Comments

Column 2 of A234760

Examples

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

Links

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

Formula

Empirical: a(n) = 27*a(n-1) -26*a(n-2) -884*a(n-3) +1597*a(n-4) +7345*a(n-5) -14758*a(n-6) -23881*a(n-7) +52625*a(n-8) +29984*a(n-9) -81577*a(n-10) -7015*a(n-11) +51495*a(n-12) -7850*a(n-13) -9139*a(n-14) +1340*a(n-15) +518*a(n-16) -36*a(n-17)