A204564 Number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..3 introduced in row major order

8, 482, 158981, 226207388, 1331721926667, 32661078401030941, 3362962064457744565685, 1461449454372060333546626590

Offset

1,1

Comments

Diagonal of A204572

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Sequence in context: A054326 A203526 A210117 * A152495 A197096 A332148

Adjacent sequences: A204561 A204562 A204563 * A204565 A204566 A204567

Keyword

nonn

Author

R. H. Hardin Jan 16 2012

Status

approved