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!)
A218314 Hilltop maps: number of n X 3 binary arrays indicating the locations of corresponding elements not exceeded by any king-move neighbor in a random 0..2 n X 3 array. 1
7, 63, 511, 4081, 32641, 261121, 2088919, 16710911, 133683711, 1069441121, 8555300481, 68440576001, 547509985575, 4379962908223, 35038767479807, 280302653750609, 2242361342901505, 17938411659180033, 143503460703541239 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A218319.

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) + 7*a(n-2) + 7*a(n-3) + 7*a(n-4) + 7*a(n-5).

Empirical g.f.: 7*x*(1 + x + x^2)^2 / (1 - 7*x - 7*x^2 - 7*x^3 - 7*x^4 - 7*x^5). - Colin Barker, Jul 24 2018

EXAMPLE

Some solutions for n=3:

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

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

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

CROSSREFS

Cf. A218319.

Sequence in context: A320073 A218191 A218367 * A218633 A218283 A218237

Adjacent sequences:  A218311 A218312 A218313 * A218315 A218316 A218317

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 25 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 June 30 19:43 EDT 2022. Contains 354945 sequences. (Running on oeis4.)