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A210820 Number of (n+1)X(n+1) 0..3 symmetric matrices containing all values 0..3 with every 2X2 subblock having two or four distinct values, and new values 0..3 introduced in lower triangle row major order 0
0, 5, 350, 27048, 3100695, 592034865, 197411860692, 117689225496746, 126916285441085904, 249072860973467032724 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

Some solutions for n=3

..0..0..2..3....0..1..0..0....0..1..0..0....0..1..0..3....0..1..0..2

..0..1..3..3....1..1..1..1....1..1..1..0....1..1..1..2....1..1..0..2

..2..3..3..0....0..1..2..2....0..1..2..3....0..1..2..2....0..0..1..3

..3..3..0..3....0..1..2..3....0..0..3..3....3..2..2..3....2..2..3..1

CROSSREFS

Sequence in context: A300388 A269556 A227448 * A193806 A158105 A203527

Adjacent sequences:  A210817 A210818 A210819 * A210821 A210822 A210823

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 27 2012

STATUS

approved

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Last modified July 5 20:21 EDT 2020. Contains 335473 sequences. (Running on oeis4.)