login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A141228 Number of points having maximal visibility in a cubic n x n x n lattice. 3
1, 8, 1, 8, 20, 64, 20, 32, 64, 216, 13, 432, 64, 64, 20, 32, 8, 32, 32, 216, 64, 64, 27, 8, 64, 216, 7, 32, 64, 352, 32, 216, 8, 8, 125, 64, 8, 24, 1, 8, 64, 8, 32, 24, 8, 8, 27, 8, 8, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Sequence A141227 gives the maximum number of points visible from some point. By symmetry, when a(n) is odd, the central point in the lattice can see the maximal number of points. When a(n)=1, the central point is the only such point. Apparently the numbers n in A141226 produce both the n x n and n x n x n lattices having central points with maximum visibility.

LINKS

Table of n, a(n) for n=1..50.

MATHEMATICA

Table[mx=0; pts=0; Do[cnt=0; Do[If[GCD[d-a, e-b, f-c]<2, cnt++ ], {a, n}, {b, n}, {c, n}]; If[cnt>mx, mx=cnt; pts=1, If[cnt==mx, pts++ ]], {d, n}, {e, n}, {f, n}]; pts, {n, 10}]

CROSSREFS

Cf. A141225.

Sequence in context: A081777 A198988 A098367 * A133820 A258718 A019864

Adjacent sequences:  A141225 A141226 A141227 * A141229 A141230 A141231

KEYWORD

nonn

AUTHOR

T. D. Noe, Jun 15 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 22 11:34 EDT 2019. Contains 326176 sequences. (Running on oeis4.)