|
| |
|
|
A071339
|
|
a(n) = the maximum number of lattice points touched by an origin-centered circle with radius <= n.
|
|
9
| |
|
|
1, 4, 4, 8, 8, 12, 12, 12, 12, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 36, 36, 36
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
LINKS
| Hugo Pfoertner, FORTRAN program for A071339-A071347
|
|
|
FORMULA
| a(n) = max(i=0 to n^2) A004018(i)
|
|
|
EXAMPLE
| a(5 to 8)=12 because the circle with radius 5 touches 12 lattice points: (+-1,+-2), (+-2,+-1), (+-5,0), (0,+-5); but no circle touches more, until the radius is sqrt(65).
|
|
|
CROSSREFS
| Cf. A004018, A071339-A071347, A071383-A071385.
Sequence in context: A105675 A196054 A053249 * A146890 A168273 A145447
Adjacent sequences: A071336 A071337 A071338 * A071340 A071341 A071342
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Hugo Pfoertner (hugo(AT)pfoertner.org), May 22 2002
|
|
|
EXTENSIONS
| Edited by Don Reble (djr(AT)nk.ca), Nov 06 2005
|
| |
|
|
