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A353495
a(n) = 1 if the arithmetic derivative of n is of the form 4k+2, otherwise 0.
12
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
OFFSET
0
FORMULA
a(n) = 1 iff A353493(n) = 2, otherwise 0.
For all n >= 1, a(n) >= A353477(n).
EXAMPLE
For n = 135, A003415(135) = 162, which leaves the remainder 2 when divided by 4, therefore a(135) = 1.
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A353495(n) = (2==(A003415(n)%4));
CROSSREFS
Characteristic function of A327862.
Cf. also A165560, A353494.
Differs from A353477 for the first time at n=135, where A353495(135) = 1, while A353477(135) = 0.
Sequence in context: A025465 A323514 A369660 * A302047 A044940 A284261
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 22 2022
STATUS
approved