login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A233083 Number of 2 X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 in row major order. 1

%I

%S 3,14,95,662,4631,32414,226895,1588262,11117831,77824814,544773695,

%T 3813415862,26693911031,186857377214,1308001640495,9156011483462,

%U 64092080384231,448644562689614,3140511938827295,21983583571791062

%N Number of 2 X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 in row major order.

%H R. H. Hardin, <a href="/A233083/b233083.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 8*a(n-1) - 7*a(n-2) for n>3.

%F Conjectures from _Colin Barker_, Oct 07 2018: (Start)

%F G.f.: x*(3 - 10*x + 4*x^2) / ((1 - x)*(1 - 7*x)).

%F a(n) = (49 + 27*7^n) / 98 for n>1.

%F (End)

%e Some solutions for n=5:

%e ..0..1..1..3..2....0..0..1..0..2....0..1..1..3..3....0..1..0..2..0

%e ..1..3..2..2..3....2..0..1..0..0....1..1..3..3..3....0..1..0..0..0

%Y Row 2 of A233082.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 03 2013

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 5 07:33 EDT 2020. Contains 336209 sequences. (Running on oeis4.)