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!)
A218065 Number of 2 X n arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..1 2 X n array. 1
4, 6, 18, 42, 108, 268, 676, 1694, 4258, 10690, 26852, 67436, 169372, 425382, 1068370, 2683258, 6739132, 16925644, 42509556, 106764750, 268144706, 673458066, 1691421684, 4248085292, 10669266476, 26796365718, 67300335730, 169027965834 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 2 of A218064.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 4*a(n-2) + a(n-3) - 3*a(n-4) - 2*a(n-5).

Empirical g.f.: 2*x*(2 + x - 2*x^2 - 2*x^3) / ((1 - x)*(1 + x)*(1 - x - 3*x^2 - 2*x^3)). - Colin Barker, Jul 23 2018

EXAMPLE

Some solutions for n=3:

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

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

CROSSREFS

Cf. A218064.

Sequence in context: A064403 A235344 A060667 * A005959 A057393 A196570

Adjacent sequences:  A218062 A218063 A218064 * A218066 A218067 A218068

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 19 2012

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 22 04:38 EDT 2022. Contains 353933 sequences. (Running on oeis4.)