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a(n) = n / gcd(n, A309639(n)), where A309639(n) is the index of the least harmonic number H_i whose denominator (A002805) is divisible by n.
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%I #7 Dec 29 2019 19:35:07

%S 1,1,1,1,1,2,1,1,1,2,1,3,1,2,3,1,1,2,1,4,7,2,1,8,1,2,1,4,1,6,1,1,3,2,

%T 5,4,1,2,3,5,1,14,1,4,5,2,1,3,1,2,3,4,1,2,5,7,3,2,1,12,1,2,7,1,5,6,1,

%U 4,23,10,1,8,1,2,3,4,7,6,1,5,1,2,1,28,5,2,3,8,1,10,7,4,3,2,5,3,1,2,9,4,1,6,1,8,35

%N a(n) = n / gcd(n, A309639(n)), where A309639(n) is the index of the least harmonic number H_i whose denominator (A002805) is divisible by n.

%H Antti Karttunen, <a href="/A330692/b330692.txt">Table of n, a(n) for n = 1..65537</a>

%F a(n) = n/A330691(n) = n / gcd(n, A309639(n)).

%o (PARI) A330692(n) = (n/gcd(n, A309639(n)));

%Y Cf. A000961 (indices of 1's).

%Y Cf. A002805, A309639, A330691, A330742.

%K nonn

%O 1,6

%A _Antti Karttunen_, Dec 29 2019