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%I #9 Dec 05 2018 17:23:55
%S 1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,1,1,1,
%T 1,2,1,1,1,4,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,3,1,1,1,1,2,
%U 1,1,1,2,1,1,1,2,1,1,1,4,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,4,1
%N a(n) = gcd(A003557(n), A173557(n)).
%H Antti Karttunen, <a href="/A322320/b322320.txt">Table of n, a(n) for n = 1..20000</a>
%F a(n) = gcd(A003557(n), A173557(n)) = gcd(A322351(n), A322352(n)).
%F a(n) = A000010(n) / A322321(n).
%t a[n_] := If[n == 1, 1, Module[{f=FactorInteger[n]}, GCD[ Times@@ (First[#] ^(Last[#]-1)& /@ f), Times@@((#-1)& @@@ f)]]]; Array[a, 120] (* _Amiram Eldar_, Dec 05 2018 *)
%o (PARI)
%o A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); }; \\ From A003557
%o A173557(n) = factorback(apply(p -> p-1, factor(n)[, 1]));
%o A322320(n) = gcd(A173557(n), A003557(n));
%Y Cf. A000010, A003557, A173557, A322321, A322351, A322352.
%Y Cf. also A066086, A322318.
%K nonn
%O 1,12
%A _Antti Karttunen_, Dec 05 2018
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