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!)
A222868 Number of n X 2 0..5 arrays with no element equal to another at a city block distance of exactly two, and new values 0..5 introduced in row major order. 1
2, 7, 34, 370, 5314, 82690, 1313794, 20983810, 335593474, 5368905730, 85900132354, 1374392680450, 21990245138434, 351843771219970, 5629499735539714, 90071993352716290, 1441151883979784194, 23058430105021841410 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A222871.
LINKS
FORMULA
Empirical: a(n) = 21*a(n-1) - 84*a(n-2) + 64*a(n-3) for n>5.
Empirical g.f.: x*(2 - 35*x + 55*x^2 + 116*x^3 - 48*x^4) / ((1 - x)*(1 - 4*x)*(1 - 16*x)). - Colin Barker, Aug 16 2018
EXAMPLE
Some solutions for n=3:
..0..0....0..1....0..0....0..0....0..1....0..1....0..1....0..1....0..1....0..1
..1..2....2..2....1..2....1..2....2..3....0..2....0..2....2..1....2..3....2..3
..1..3....1..3....3..4....1..2....1..0....3..4....3..3....3..3....4..5....4..4
CROSSREFS
Cf. A222871.
Sequence in context: A110313 A000944 A136310 * A222777 A222891 A342411
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 07 2013
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 March 2 21:56 EST 2024. Contains 370498 sequences. (Running on oeis4.)