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A322321 a(n) = lcm(A003557(n), A173557(n)).

%I A322321 #9 Dec 05 2018 17:24:01
%S A322321 1,1,2,2,4,2,6,4,6,4,10,2,12,6,8,8,16,6,18,4,12,10,22,4,20,12,18,6,28,
%T A322321 8,30,16,20,16,24,6,36,18,24,4,40,12,42,10,24,22,46,8,42,20,32,12,52,
%U A322321 18,40,12,36,28,58,8,60,30,12,32,48,20,66,16,44,24,70,12,72,36,40,18,60,24,78,8,54,40,82,12,64,42,56,20
%N A322321 a(n) = lcm(A003557(n), A173557(n)).
%H A322321 Antti Karttunen, <a href="/A322321/b322321.txt">Table of n, a(n) for n = 1..10000</a>
%H A322321 <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a>
%F A322321 a(n) = lcm(A003557(n), A173557(n)) = lcm(A322351(n), A322352(n)).
%F A322321 a(n) = A000010(n) / A322320(n).
%t A322321 a[n_] := If[n == 1, 1, Module[{f=FactorInteger[n]}, LCM[ Times@@ (First[#] ^(Last[#]-1)& /@  f), Times@@((#-1)& @@@ f)]]]; Array[a, 120] (* _Amiram Eldar_, Dec 05 2018 *)
%o A322321 (PARI)
%o A322321 A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); }; \\ From A003557
%o A322321 A173557(n) = factorback(apply(p -> p-1, factor(n)[, 1]));
%o A322321 A322321(n) = lcm(A003557(n), A173557(n));
%Y A322321 Cf. A000010, A003557, A173557, A322320, A322351, A322352.
%Y A322321 Cf. also A322319, A322359.
%K A322321 nonn
%O A322321 1,3
%A A322321 _Antti Karttunen_, Dec 05 2018