OFFSET
1,1
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
EXAMPLE
For n=9, its first arithmetic derivative is A003415(9) = 6, its second derivative is A003415(6) = 5, and its third derivative is A003415(5) = 1, and 1 is a squarefree number (in A005117), thus 9 is included in this sequence.
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 11 2019
STATUS
approved