A232517 Number of (2+1)X(n+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally, with no adjacent elements equal

4, 52, 32, 326, 250, 2138, 1956, 13976, 14782, 91760, 109522, 604450, 799026, 3994420, 5761416, 26475334, 41161880, 175967762, 291918330, 1172568978, 2057927044, 7831923864, 14436579566, 52424836208, 100861979186, 351610320834

Offset

1,1

Comments

Row 2 of A232515

Links

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

Formula

Empirical: a(n) = 6*a(n-2) +a(n-3) +3*a(n-4) +a(n-5) -2*a(n-6) -2*a(n-7).

Empirical: G.f.: -2*x*(-2-26*x-4*x^2-5*x^3+3*x^4+5*x^5+5*x^6) / ( 1-6*x^2-x^3-3*x^4-x^5+2*x^6+2*x^7 ). - R. J. Mathar, Nov 23 2014

Example

Some solutions for n=7
..1..0..1..0..1..0..1..0....0..1..2..0..1..2..1..2....2..1..0..1..2..1..2..1
..1..2..1..2..1..2..1..0....2..1..2..0..1..2..1..0....2..1..0..1..2..1..0..1
..1..0..1..0..1..2..1..2....0..1..2..0..1..2..1..0....0..1..0..1..2..1..2..1

Crossrefs

Sequence in context: A000516 A182044 A000854 * A329009 A110908 A232507

Adjacent sequences: A232514 A232515 A232516 * A232518 A232519 A232520

Keyword

nonn

Author

R. H. Hardin, Nov 25 2013

Status

approved