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!)
A303632 Number of nX4 0..1 arrays with every element unequal to 2 or 3 horizontally or vertically adjacent elements, with upper left element zero. 1
0, 2, 1, 4, 8, 22, 47, 123, 302, 784, 1961, 5002, 12715, 32486, 82753, 211121, 538371, 1373975, 3505385, 8944576, 22822438, 58237614, 148606194, 379208575, 967645940, 2469221128, 6300909758, 16078584921, 41029120473, 104697723446, 267166736204 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A303636.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) +a(n-2) -5*a(n-3) +a(n-4) -4*a(n-5) -9*a(n-6) -a(n-7) +39*a(n-8) -5*a(n-9) -26*a(n-10) +22*a(n-11) -a(n-12) +a(n-13) -8*a(n-14) -a(n-15) +2*a(n-16)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A303636.

Sequence in context: A294061 A113820 A319479 * A133267 A145864 A306392

Adjacent sequences:  A303629 A303630 A303631 * A303633 A303634 A303635

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 27 2018

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 July 4 05:35 EDT 2022. Contains 355064 sequences. (Running on oeis4.)