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!)
A269197 Number of n X 4 0..3 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling three no more than once. 1
216, 9612, 400428, 15289548, 555862380, 19558138380, 672230393004, 22702294138188, 756261535626732, 24917784636315276, 813662963240248620, 26370904678702613964, 849277413026034547308, 27202597468298860880652 (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) = 62*a(n-1) - 1031*a(n-2) + 2180*a(n-3) - 1535*a(n-4) + 350*a(n-5) - 25*a(n-6) for n>7.

Empirical g.f.: 12*x*(18 - 315*x + 2265*x^2 - 8158*x^3 + 10756*x^4 - 4951*x^5 + 897*x^6) / ((1 - x)^2*(1 - 30*x + 5*x^2)^2). - Colin Barker, Jan 20 2019

EXAMPLE

Some solutions for n=2:

..1..0..0..1. .1..3..1..2. .3..1..0..1. .0..2..2..2. .1..0..1..3

..0..1..1..3. .2..3..2..3. .0..1..3..2. .3..2..3..0. .1..1..1..0

CROSSREFS

Column 4 of A269201.

Sequence in context: A131643 A269139 A231319 * A259831 A269105 A223359

Adjacent sequences:  A269194 A269195 A269196 * A269198 A269199 A269200

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 20 2016

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 27 15:29 EDT 2020. Contains 337383 sequences. (Running on oeis4.)