A192841 - OEIS

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A192841

Number of n X n symmetric 0..2 arrays with each element equal to at least two horizontal or vertical neighbors, containing at least one 2 and with new values 0..2 introduced in lower triangular row major order

0, 0, 0, 1, 11, 346, 8731, 349401, 20156718, 1851292543, 266585533037, 61535828576431, 22709782832888746, 13463873321548595944, 12814751672955863921345

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,5

LINKS

Table of n, a(n) for n=1..15.

EXAMPLE

Some solutions for 6X6

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

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

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

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

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