A267904 Number of 4Xn arrays containing n copies of 0..4-1 with every element equal to at least one horizontal or vertical neighbor and the top left element equal to 0.

0, 30, 138, 17658, 414138, 28493946, 1246334388, 72638390592, 3823498828854, 218021286182580

Offset

1,2

Comments

Row 4 of A267901.

Links

Table of n, a(n) for n=1..10.

Example

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

Crossrefs

Cf. A267901.

Sequence in context: A348828 A158462 A064495 * A218407 A347222 A229450

Adjacent sequences: A267901 A267902 A267903 * A267905 A267906 A267907

Keyword

nonn

Author

R. H. Hardin, Jan 22 2016

Status

approved