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 A318304 a(n) = A083254(n)/A003557(n) = (2*A173557(n) - A007947(n)). 3

%I

%S 1,0,1,0,3,-2,5,0,1,-2,9,-2,11,-2,1,0,15,-2,17,-2,3,-2,21,-2,3,-2,1,

%T -2,27,-14,29,0,7,-2,13,-2,35,-2,9,-2,39,-18,41,-2,1,-2,45,-2,5,-2,13,

%U -2,51,-2,25,-2,15,-2,57,-14,59,-2,3,0,31,-26,65,-2,19,-22,69,-2,71,-2,1,-2,43,-30,77,-2,1,-2,81,-18,43,-2,25

%N a(n) = A083254(n)/A003557(n) = (2*A173557(n) - A007947(n)).

%H Antti Karttunen, <a href="/A318304/b318304.txt">Table of n, a(n) for n = 1..65537</a>

%F a(n) = A083254(n)/A003557(n) = 2*A173557(n) - A007947(n).

%F a(n) = A173557(n) - A318305(n).

%o (PARI)

%o A173557(n) = my(f=factor(n)[, 1]); prod(k=1, #f, f[k]-1); \\ From A173557

%o A007947(n) = factorback(factorint(n)[, 1]); \\ From A007947

%o A318304(n) = (2*A173557(n) - A007947(n));

%o (PARI)

%o A083254(n) = (2*eulerphi(n)-n);

%o A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); }; \\ From A003557

%o A318304(n) = (A083254(n)/A003557(n));

%Y Cf. A000010, A003557, A007947, A083254, A173557, A318305.

%K sign

%O 1,5

%A _Antti Karttunen_, Aug 26 2018

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Last modified May 24 00:38 EDT 2019. Contains 323528 sequences. (Running on oeis4.)