Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #6 Dec 28 2020 17:48:14
%S 0,1,1,3,1,5,1,7,2,9,1,11,1,13,7,15,1,17,1,19,5,21,1,23,3,25,13,9,1,
%T 29,1,31,8,33,17,35,1,37,19,39,1,41,1,43,11,45,1,47,4,49,25,17,1,53,
%U 27,55,14,57,1,59,1,61,31,63,4,13,1,67,17,23,1,71,1,73,37,25,19,77,1,79,5,81,1,83,21,85,43,87,1,89,5,91,23
%N a(n) = (n-1) / gcd(n-1, A003958(n)).
%H Antti Karttunen, <a href="/A340083/b340083.txt">Table of n, a(n) for n = 1..8191</a>
%H Antti Karttunen, <a href="/A340083/a340083.txt">Data supplement: n, a(n) computed for n = 1..65537</a>
%F a(n) = (n-1) / A340081(n) = (n-1) / gcd(n-1, A003958(n)).
%o (PARI)
%o A003958(n) = if(1==n,n,my(f=factor(n)); for(i=1,#f~,f[i,1]--); factorback(f));
%o A340083(n) = ((n-1)/gcd(n-1, A003958(n)));
%Y Cf. A003958, A340081, A340082.
%Y Cf. also A160596, A340073.
%K nonn
%O 1,4
%A _Antti Karttunen_, Dec 28 2020