login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A210855 Number of (n+1)X(n+1) 0..2 symmetric matrices with every 2X2 subblock having one or two distinct values, and new values 0..2 introduced in lower triangle row major order 1

%I

%S 4,46,1139,55516,5327304,1010944060,380704421087,285205710360936,

%T 425825333933157003,1268871858354238286927,7554384371145384136117854,

%U 89942576436863983961350601461,2143078341798100623746679385130235

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

%H R. H. Hardin, <a href="/A210855/b210855.txt">Table of n, a(n) for n = 1..16</a>

%e Some solutions for n=3

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 28 2012

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 25 18:25 EDT 2022. Contains 354071 sequences. (Running on oeis4.)