A233100 Number of 3 X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 in row major order.

10, 74, 941, 11486, 141566, 1742447, 21452183, 264098522, 3251348462, 40027693247, 492785243519, 6066732018746, 74688189381254, 919494319284479, 11319993299254919, 139361653035025178, 1715696275016282462

Offset

1,1

Links

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

Formula

Empirical: a(n) = 13*a(n-1) - 5*a(n-2) - 47*a(n-3) + 52*a(n-4) - 12*a(n-5) for n>6.

Empirical g.f.: x*(10 - 56*x + 29*x^2 + 93*x^3 - 89*x^4 + 18*x^5) / ((1 - x)*(1 - 12*x - 7*x^2 + 40*x^3 - 12*x^4)). - Colin Barker, Oct 07 2018

Example

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

Crossrefs

Row 3 of A233098.

Sequence in context: A264082 A103434 A119167 * A266674 A233455 A027778

Adjacent sequences: A233097 A233098 A233099 * A233101 A233102 A233103

Keyword

nonn

Author

R. H. Hardin, Dec 04 2013

Status

approved