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Number of prime divisors of sigma(n) that are larger than the largest prime factor of n; a(1) = 0.
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%I #8 Jul 20 2020 02:08:57

%S 0,1,0,1,0,0,0,2,1,0,0,1,0,0,0,1,0,1,0,1,0,0,0,1,1,0,1,0,0,0,0,2,0,0,

%T 0,2,0,0,0,0,0,0,0,0,1,0,0,1,1,1,0,0,0,1,0,0,0,0,0,1,0,0,1,1,0,0,0,0,

%U 0,0,0,2,0,0,1,0,0,0,0,1,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,1,1,2,0,0,0,0,0

%N Number of prime divisors of sigma(n) that are larger than the largest prime factor of n; a(1) = 0.

%H Antti Karttunen, <a href="/A336352/b336352.txt">Table of n, a(n) for n = 1..65537</a>

%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>

%F For all n >= 1, a(n) <= A058062(n).

%o (PARI) A336352(n) = if(1==n,0,my(gp=vecmax(factor(n)[, 1])); #select(p -> (p>gp), factor(sigma(n))[, 1]));

%Y Cf. A000203, A006530, A058062, A336353 (positions of zeros).

%K nonn

%O 1,8

%A _Antti Karttunen_, Jul 19 2020