OFFSET
1,1
COMMENTS
Numbers n > 1 for which the smallest r such that r^k <= spf(n) and gpf(n) < r^(k+1) [for some k >= 0] is gpf(n)+1. Here spf and gpf (smallest and greatest prime factor of n) are given by A020639(n) and A006530(n). (The original, equivalent definition of the sequence).
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
PROG
(Scheme with Antti Karttunen's IntSeq-library, three alternative versions)
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 17 2014. A new simpler definition found Jan 01 2015 and the original definition moved to the Comments section
STATUS
approved