OFFSET
2,1
COMMENTS
2*[2n/3] is an upper bound for a(n). - Jud McCranie, Aug 12 2001
This bound is achieved for n=2, 4 and 6-65.
Conjecture: a(n) = 2*[2n/3] for n >= 6. - Alexander D. Healy, Feb 10 2024
REFERENCES
Martin Gardner, The Last Recreations, Copernicus, NY, 1997, 274-283.
LINKS
Alexander D. Healy, Examples of optimal placements for n <= 65
CROSSREFS
KEYWORD
nonn,nice,more
AUTHOR
Robert Trent (trentrd(AT)hotmail.com), Aug 23 2000
EXTENSIONS
a(12)-a(65) from Alexander D. Healy, Feb 10 2024
STATUS
approved