OFFSET
1,1
COMMENTS
Kravitz conjectured that no numbers exist whose abundance is a positive odd square. The squares of this sequence are counterexamples.
a(12) <= 37379475098. a(13) <= 56559884906. - Donovan Johnson, Apr 07 2011
REFERENCES
Guy, R. K. Unsolved Problems in Number Theory, 3rd ed. New York: Springer-Verlag, 2004, page 74.
LINKS
Eric Weisstein, Kravitz Conjecture
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Ed Pegg Jr, Apr 01 2011
EXTENSIONS
More terms, page number in Guy, cross references.
a(9)-a(11) from Donovan Johnson, Apr 07 2011
STATUS
approved