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A251142 Number of (n+1) X (n+1) 0..2 arrays with every 2 X 2 subblock summing to 4 and no 2 X 2 subblock having exactly two nonzero entries. 0
13, 49, 143, 401, 1061, 2763, 7101, 18193, 46575, 119441, 307045, 791499, 2045725 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Diagonal of A251149.

LINKS

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

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A251149.

Sequence in context: A158480 A009951 A274974 * A146287 A147346 A147452

Adjacent sequences:  A251139 A251140 A251141 * A251143 A251144 A251145

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 30 2014

STATUS

approved

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Last modified August 18 18:04 EDT 2017. Contains 290732 sequences.