A223557 Petersen graph (3,1) coloring a rectangular array: number of 2 X n 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,3 3,5 3,4 1,2 1,4 4,5 2,0 2,5 and every array movement to a horizontal or antidiagonal neighbor moves along an edge of this graph, with the array starting at 0.

6, 27, 171, 1089, 6939, 44217, 281763, 1795473, 11441259, 72906921, 464583411, 2960456193, 18864859707, 120212193177, 766025913411, 4881332621169, 31105224694539, 198211242377097, 1263057797861523, 8048559615522273

Offset

1,1

Comments

Row 2 of A223556.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) - 4*a(n-2) for n>3.

Empirical g.f.: 3*x*(2 - x)*(1 - 2*x) / (1 - 7*x + 4*x^2). - Colin Barker, Aug 21 2018

Example

Some solutions for n=3:
..0..1..0....0..3..4....0..1..0....0..1..0....0..1..0....0..2..1....0..3..0
..0..2..5....4..5..2....0..3..0....0..2..1....0..1..0....1..2..1....4..1..4

Crossrefs

Cf. A223556.

Sequence in context: A144013 A318565 A092854 * A289022 A060977 A267630

Adjacent sequences: A223554 A223555 A223556 * A223558 A223559 A223560

Keyword

nonn

Author

R. H. Hardin, Mar 22 2013

Status

approved