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!)
A235673 Number of (n+1) X (2+1) 0..1 arrays with the difference between each 2 X 2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise. 1

%I

%S 58,380,2456,15790,101398,650928,4178316,26820102,172154058,

%T 1105028596,7092994476,45528746034,292241404878,1875848682364,

%U 12040758823136,77287616186486,496096276240318,3184358988382152,20439867526684676

%N Number of (n+1) X (2+1) 0..1 arrays with the difference between each 2 X 2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise.

%H R. H. Hardin, <a href="/A235673/b235673.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 8*a(n-1) - 9*a(n-2) - 9*a(n-3) + 10*a(n-4) + 3*a(n-5) - 2*a(n-6).

%F Empirical g.f.: 2*x*(29 - 42*x - 31*x^2 + 42*x^3 + 11*x^4 - 8*x^5) / ((1 - x)*(1 - x - x^2)*(1 - 6*x - 3*x^2 + 2*x^3)). - _Colin Barker_, Oct 19 2018

%e Some solutions for n=5:

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

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

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

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

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

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

%Y Column 2 of A235679.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 13 2014

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 September 25 18:51 EDT 2021. Contains 347659 sequences. (Running on oeis4.)