login
A327861
Number of divisors d of n for which A003415(d)*d is equal to n, where A003415(x) gives the arithmetic derivative of x.
2
0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0
OFFSET
1,4153248
COMMENTS
Number of times n occurs in A190116.
LINKS
EXAMPLE
a(4153248)=2 as out of 192 divisors of 4153248, only 1368 and 2277 are such that 1368 * A003415(1368) = 2277 * A003415(2277) = 4153248.
PROG
(PARI)
A003415(n) = {my(fac); if(n<1, 0, fac=factor(n); sum(i=1, matsize(fac)[1], n*fac[i, 2]/fac[i, 1]))}; \\ From A003415
A327861(n) = sumdiv(n, d, (d*A003415(d) == n));
CROSSREFS
Cf. also A327153, A327166, A327169.
Sequence in context: A283991 A353499 A359372 * A131929 A100821 A139689
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 28 2019
STATUS
approved