login
A341625
a(n) = 1 if the arithmetic derivative of n is less than n, otherwise 0.
4
0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1
OFFSET
0
FORMULA
a(n) = 1 if A003415(n) < n, otherwise 0.
a(n) = [A168036(n) < 0].
For all >= 1, a(n) >= A080339(n).
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A341625(n) = (A003415(n) < n);
CROSSREFS
Characteristic function of A083347.
Sequence in context: A098725 A284939 A188260 * A166486 A046978 A075553
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 28 2021
STATUS
approved