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!)
A207276 Number of n X 1 0..3 arrays avoiding the patterns z z+1 z or z z-1 z in any row, column, diagonal or antidiagonal. 4

%I

%S 4,16,58,214,788,2902,10686,39350,144902,533586,1964872,7235426,

%T 26643664,98112376,361288084,1330403818,4899066416,18040275760,

%U 66431340558,244626139148,900808977386,3317130444708,12214969725478,44980288801238

%N Number of n X 1 0..3 arrays avoiding the patterns z z+1 z or z z-1 z in any row, column, diagonal or antidiagonal.

%C Column 1 of A207283.

%H R. H. Hardin, <a href="/A207276/b207276.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) + 2*a(n-2) + a(n-3) + 3*a(n-4) + a(n-5).

%F Empirical g.f.: 2*x*(1 + x)*(2 + x^2 + x^3) / (1 - 3*x - 2*x^2 - x^3 - 3*x^4 - x^5). - _Colin Barker_, Feb 20 2018

%e Some solutions for n=4:

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

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

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

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

%Y Cf. A207283.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 16 2012

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 October 24 13:43 EDT 2021. Contains 348232 sequences. (Running on oeis4.)