The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A196537 Number of nX1 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than or equal to itself 3
1, 3, 2, 7, 19, 35, 77, 176, 377, 819, 1801, 3927, 8562, 18711, 40855, 89179, 194729, 425184, 928305, 2026855, 4425441, 9662395, 21096706, 46062279, 100571611, 219586403, 479441557, 1046805072, 2285577449, 4990293595, 10895727817 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 1 of A196544
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4).
Empirical: G.f. x*(x-1)*(x^2+3*x+1) / ( -1+x+x^2+3*x^3+x^4 ). - R. J. Mathar, Jul 25 2012
EXAMPLE
All solutions for n=4
..0....0....1....0....0....1....0
..2....1....0....2....2....1....2
..2....2....2....1....1....2....0
..0....0....0....1....0....0....1
CROSSREFS
Sequence in context: A104528 A177115 A316087 * A173099 A111928 A348695
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 03 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 24 11:42 EDT 2024. Contains 372773 sequences. (Running on oeis4.)