A198711 Number of n X 4 0..3 arrays with values 0..3 introduced in row major order and no element equal to any horizontal or vertical neighbor.

5, 172, 6548, 250031, 9548295, 364637102, 13925032958, 531779578441, 20307996787865, 775536991678112, 29616787512285048, 1131028064429979731, 43192546862380323515, 1649469330720040937602, 62991170251091380482818

Offset

1,1

Comments

Column 4 of A198715.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 46*a(n-1) - 312*a(n-2) + 530*a(n-3) - 263*a(n-4).

Empirical g.f.: x*(5 - 58*x + 196*x^2 - 163*x^3) / ((1 - x)*(1 - 45*x + 267*x^2 - 263*x^3)). - Colin Barker, Mar 02 2018

Example

Some solutions with all values from 0 to 3 for n=5:
..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
..1..0..2..0....1..0..1..2....1..0..1..2....1..0..1..0....1..0..1..0
..0..2..0..3....2..1..3..1....3..1..0..1....2..1..0..3....2..1..3..1
..2..1..2..0....1..2..0..3....1..0..3..0....3..2..1..0....3..0..1..3
..1..2..1..2....2..3..1..2....2..1..0..1....2..1..3..2....2..3..0..1

Crossrefs

Cf. A198715.

Sequence in context: A210832 A206393 A220640 * A210927 A139986 A354573

Adjacent sequences: A198708 A198709 A198710 * A198712 A198713 A198714

Keyword

nonn

Author

R. H. Hardin, Oct 29 2011

Status

approved