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!)
A196132 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,3,4 for x=0,1,2,3,4. 1
0, 4, 3, 8, 14, 19, 46, 56, 133, 184, 372, 599, 1064, 1874, 3147, 5692, 9516, 17053, 28980, 51004, 88089, 153086, 266660, 461205, 804810, 1392380, 2426083, 4205680, 7313450, 12699273, 22056242, 38328650, 66544359, 115648570, 200804584 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 3's, every 4 is next to 4 4's.

Column 2 of A196138.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 3*a(n-2) +2*a(n-3) -2*a(n-4) -3*a(n-5) -a(n-6) +4*a(n-7) -2*a(n-9).

Empirical g.f.: x^2*(4 + 3*x - 4*x^2 - 3*x^3 - 3*x^4 + 6*x^5 - 4*x^7) / ((1 - x)*(1 + x - 2*x^2 - 4*x^3 - 2*x^4 + x^5 + 2*x^6 - 2*x^7 - 2*x^8)). - Colin Barker, May 08 2018

EXAMPLE

All solutions for n=4:

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

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

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

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

CROSSREFS

Cf. A196138.

Sequence in context: A309517 A105185 A165739 * A198179 A137503 A320263

Adjacent sequences:  A196129 A196130 A196131 * A196133 A196134 A196135

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 28 2011

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 February 25 22:28 EST 2021. Contains 341618 sequences. (Running on oeis4.)