OFFSET
1,2
COMMENTS
a(18) = 42945966786, but a(17) > 5*10^10.
LINKS
R. B. Eggleton, J. S. Kimberley and J. A. MacDougall, Square-free rank of integers, Journal of Combinatorial Mathematics and Combinatorial Computing Vol. 106, Issue August 2018, p. 185-207.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Jason Kimberley, Feb 15 2017
STATUS
approved