OFFSET
1,1
COMMENTS
Those terms that are > ceiling(sqrt(n*(n+1)*(2n+1)/3)) are only the best currently known solutions. - Larry Reeves (larryr(AT)acm.org), Apr 19 2001
a(1)-a(17) except a(15) are known to be the smallest possible. - Sean A. Irvine, Dec 13 2022
LINKS
E. J. Friedman, Math. Magic: August 1999, Question #2
Sean A. Irvine, Java program (github)
Sean A. Irvine, Solution for a(16)
Sean A. Irvine, Solution for a(17)
FORMULA
a(n) >= sqrt(n*(n+1)*(2n+1)/3).
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Jason Earls, Apr 18 2001
EXTENSIONS
Data updated from values at Friedman link by Sean A. Irvine, Dec 05 2022
a(16) from Sean A. Irvine, Dec 13 2022
a(17) from Sean A. Irvine, Dec 17 2022
STATUS
approved