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Sum of numerator and denominator of product{p|n,p=primes} (1 -1/p).
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%I #10 Aug 16 2019 14:02:34

%S 2,3,5,3,9,4,13,3,5,7,21,4,25,10,23,3,33,4,37,7,11,16,45,4,9,19,5,10,

%T 57,19,61,3,53,25,59,4,73,28,21,7,81,9,85,16,23,34,93,4,13,7,83,19,

%U 105,4,19,10,31,43,117,19,121,46,11,3,113,43,133,25,113,47,141,4,145,55,23,28

%N Sum of numerator and denominator of product{p|n,p=primes} (1 -1/p).

%F a(n) = A076511(n) + A076512(n). - _Michel Marcus_, Aug 16 2019

%e a(12) = 4 = 1+3 because (1 -1/2)(1 -1/3) = 1/3.

%p a:=proc(n) local b,ct,f; with(numtheory): b:=convert(factorset(n),list): ct:=nops(b): f:=simplify(product(1-1/b[j],j=1..ct)):numer(f)+denom(f) end: seq(a(n),n=1..100); # _Emeric Deutsch_, May 28 2005

%Y Cf. A076511, A076512.

%K nonn

%O 1,1

%A _Leroy Quet_, May 27 2005

%E More terms from _Emeric Deutsch_, May 28 2005