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A211109 1/4 the number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having two, three or four distinct values 1
15, 891, 208575, 192515373, 700590250755, 10052185332068649, 568662258529219221297, 126836971252795362522842613, 111541083171262765512515480985165 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

EXAMPLE

Some solutions for n=3

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

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

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

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

CROSSREFS

Sequence in context: A258796 A232364 A264562 * A249963 A157462 A268166

Adjacent sequences:  A211106 A211107 A211108 * A211110 A211111 A211112

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 31 2012

STATUS

approved

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Last modified September 17 06:16 EDT 2021. Contains 347478 sequences. (Running on oeis4.)