%I #10 May 09 2022 11:02:42
%S 1,1,1,1,1,1,1,1,1,16,1,1,1,1,7,1,1,1,1,1,5,16,1,1,1,1,1,1,1,112,1,1,
%T 49,13,45,1,1,1,7,16,1,5,1,1,1,16,1,1,1,1,7,64,1,1,112,1,49,16,1,7,1,
%U 1,1,1,9,784,1,1,5,720,1,1,1,1,1,1,5,7,1,1,1,16,1,5,117,1,7,16,1,16,45,1,147,16,7
%N a(n) = A353802(n) / gcd(A051027(n), A353802(n)), where A051027(n) = sigma(sigma(n)), and A353802(n) = Product_{p^e||n} sigma(sigma(p^e)).
%C Numerator of fraction A353802(n) / A051027(n).
%H Antti Karttunen, <a href="/A353806/b353806.txt">Table of n, a(n) for n = 1..20000</a>
%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F a(n) = A353802(n) / A353804(n) = A353802(n) / gcd(A051027(n), A353802(n)).
%o (PARI)
%o A051027(n) = sigma(sigma(n));
%o A353806(n) = { my(f = factor(n), u=prod(k=1, #f~, A051027(f[k, 1]^f[k, 2]))); (u / gcd(A051027(n), u)); };
%Y Cf. A000203, A051027, A353802, A353803, A353804, A353805 (denominators).
%Y Cf. A336547 (positions of 1's), A336548 (positions of terms > 1), see also A353807.
%Y Cf. also A353755, A353756.
%K nonn,frac
%O 1,10
%A _Antti Karttunen_, May 08 2022
|