VOOZH about

URL: https://oeis.org/A023393

⇱ A023393 - OEIS

login
A023393
Maximal number of circles of radius 1 that can be packed in a circle of radius n.
10
0, 1, 2, 7, 11, 19, 27, 38, 50, 64, 80, 98, 118
OFFSET
0,3
COMMENTS
The terms for n>5 are only conjectures supported by extensive computations.
REFERENCES
R. L. Graham and B. D. Lubachevsky, Dense packings of 3k(k+1)+1 equal disks in a circle for k = 1, 2, 3, 4 and 5, Proc. First Int. Conf. "Computing and Combinatorics" COCOON'95, Springer Lecture Notes in Computer Science 959 (1996), 303-312.
For list of references given by E. Specht, see the Specht link.
LINKS
R. L. Graham, B. D. Lubachevsky, K. J. Nurmela, and P. R. J. Östergård, Dense Packings of Congruent Circles in a Circle, Discrete Mathematics 181 (1998), 139-154.
B. D. Lubachevsky and R. L. Graham, Curved Hexagonal Packings of Equal Disks in a Circle, Discrete Comput. Geom. 18 (1997), 179-194.
CROSSREFS
Cf. A201993 (conjectured lower bounds for a(n)).
Sequence in context: A105881 A060191 A178899 * A084619 A236478 A106906
KEYWORD
more,nonn,hard
EXTENSIONS
Terms for n>5 from Hugo Pfoertner, Jun 01 2003
Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Feb 18 2004, writes to suggest that the sequence probably continues 138, 161, 187, 213, 242, 272, 304, 337, 373, 413, 451, 495, ...
Edited by N. J. A. Sloane at the suggestion of David W. Wilson, Sep 22 2007
Offset corrected by Jon E. Schoenfield, Oct 12 2008
STATUS
approved