A198251 Number of 2nX12 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors

51, 90641, 203087097, 468268681671, 1088857594220452

Offset

1,1

Comments

Column 6 of A198253

Links

Table of n, a(n) for n=1..5.

Example

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

Crossrefs

Sequence in context: A208412 A198904 A238567 * A135531 A038777 A281979

Adjacent sequences: A198248 A198249 A198250 * A198252 A198253 A198254

Keyword

nonn

Author

R. H. Hardin Oct 22 2011

Status

approved