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 A210828 Number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in lower triangle row major order 0

%I #4 Mar 31 2012 12:37:34

%S 4,47,1307,77587,9532771,2382934915,1203182006883,1223431341113467,

%T 2503405292687579547,10310784667022325909483,

%U 85532677566328699199301659,1430104344703313378401501706139,48228702523491961059131488089168571

%N Number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in lower triangle row major order

%e Some solutions for n=3

%e ..0..1..1..1....0..1..0..1....0..1..1..0....0..1..1..1....0..1..2..1

%e ..1..1..1..1....1..0..1..1....1..0..1..0....1..0..1..1....1..1..1..2

%e ..1..1..1..1....0..1..1..1....1..1..0..1....1..1..1..2....2..1..2..2

%e ..1..1..1..2....1..1..1..0....0..0..1..1....1..1..2..1....1..2..2..1

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 27 2012

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Last modified December 9 18:33 EST 2023. Contains 367693 sequences. (Running on oeis4.)