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!)
A253454 Number of (n+1) X (6+1) 0..2 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally and vertically. 1
19701, 31630, 39463, 52912, 83003, 147332, 285681, 590963, 1287225, 2936843, 7007361, 17462243, 45313545, 121840763, 337369041, 955847123, 2755067865, 8040303083, 23671154721, 70114001603, 208543126185, 622031667803 (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) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) for n>9.

Empirical: a(n) = 529*3^(n-3) + 3431*2^(n-1) + 23248 for n>6.

Empirical g.f.: x*(19701 - 86576*x + 66394*x^2 + 45858*x^3 + 9844*x^4 - 5432*x^5 - 2750*x^6 - 489*x^7 - 54*x^8) / ((1 - x)*(1 - 2*x)*(1 - 3*x)). - Colin Barker, Dec 13 2018

EXAMPLE

Some solutions for n=4:

..0..1..1..0..1..0..0....0..1..0..2..2..2..2....0..2..1..1..2..0..1

..2..2..2..1..2..1..1....2..2..0..1..0..0..0....0..2..1..1..2..0..1

..1..1..1..0..1..0..0....2..2..0..1..0..0..0....0..2..1..1..2..0..1

..1..1..1..0..1..0..0....2..2..0..1..0..0..1....0..2..1..1..2..0..1

..2..2..2..1..2..1..1....2..2..0..1..0..0..2....0..2..1..1..2..0..2

CROSSREFS

Column 6 of A253456.

Sequence in context: A288885 A253493 A253500 * A237096 A252206 A206508

Adjacent sequences:  A253451 A253452 A253453 * A253455 A253456 A253457

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 01 2015

STATUS

approved

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 28 10:48 EDT 2021. Contains 347714 sequences. (Running on oeis4.)