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A192639 Number of n X n symmetric 0..2 arrays with each element equal to at least one horizontal or vertical neighbor and any new values 0..2 introduced in lower triangular row major order 0
0, 1, 5, 120, 7335, 1156521, 457780079, 457756056728, 1154866876506535, 7352987974445171007, 118143153320894808308264, 4790379823545169735782598423, 490170667588709471795216706934694 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

Some solutions for 6X6 containing a 2

..0..0..0..2..2..1....0..0..0..1..1..2....0..0..0..0..2..0....0..0..0..0..0..0

..0..0..0..0..2..1....0..0..0..2..2..2....0..0..0..1..2..0....0..0..0..0..2..2

..0..0..1..1..2..2....0..0..1..1..2..0....0..0..0..1..0..0....0..0..0..1..1..2

..2..0..1..0..0..0....1..2..1..2..2..0....0..1..1..2..2..1....0..0..1..0..0..1

..2..2..2..0..1..1....1..2..2..2..2..0....2..2..0..2..2..1....0..2..1..0..1..1

..1..1..2..0..1..1....2..2..0..0..0..0....0..0..0..1..1..1....0..2..2..1..1..1

CROSSREFS

Sequence in context: A158564 A252928 A308363 * A099123 A097993 A172806

Adjacent sequences:  A192636 A192637 A192638 * A192640 A192641 A192642

KEYWORD

nonn

AUTHOR

R. H. Hardin Jul 06 2011

STATUS

approved

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Last modified June 20 10:13 EDT 2019. Contains 324234 sequences. (Running on oeis4.)