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!)
A253155 Number of (n+1) X (4+1) 0..1 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally and vertically. 1
109, 120, 129, 164, 236, 380, 668, 1244, 2396, 4700, 9308, 18524, 36956, 73820, 147548, 295004, 589916, 1179740, 2359388, 4718684, 9437276, 18874460, 37748828, 75497564, 150995036, 301989980, 603979868, 1207959644, 2415919196, 4831838300 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) for n>5.

Empirical: a(n) = 9*2^(n-1) + 92 for n>3.

Empirical g.f.: x*(109 - 207*x - 13*x^2 + 17*x^3 + 2*x^4) / ((1 - x)*(1 - 2*x)). - Colin Barker, Dec 09 2018

EXAMPLE

Some solutions for n=6:

..0..1..1..1..1....0..0..0..0..0....1..0..0..0..1....0..0..0..1..0

..0..0..0..0..0....1..1..1..1..1....1..0..0..0..1....1..0..0..1..0

..1..1..1..1..1....1..1..1..1..1....1..0..0..0..1....1..0..0..1..0

..1..1..1..1..1....1..1..1..1..1....1..0..0..0..1....1..0..0..1..0

..0..0..0..0..0....0..0..0..0..0....1..0..0..0..1....1..0..0..1..0

..0..0..0..0..0....1..1..1..1..1....1..0..0..0..1....1..0..0..1..0

..0..0..0..0..1....0..0..0..0..0....1..0..0..0..1....1..0..0..1..1

CROSSREFS

Column 4 of A253159.

Sequence in context: A196673 A159027 A039492 * A095609 A046295 A164288

Adjacent sequences:  A253152 A253153 A253154 * A253156 A253157 A253158

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 28 2014

STATUS

approved

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 28 22:08 EDT 2022. Contains 354122 sequences. (Running on oeis4.)