%I #10 Oct 11 2019 16:27:21
%S 6,10,12,18,22,24,28,34,36,40,48,52,54,58,72,76,82,88,100,108,112,118,
%T 142,148,160,162,165,172,184,192,196,202,208,210,214,232,250,268,273,
%U 274,288,298,316,345,352,358,382,384,385,388,390,394,399,400,412,420
%N Composites in sequence A114518.
%e 24 is a composite. 24 = 2^3 * 3 and 2^3 + 3 = 11, which is prime. So 24 is in the sequence.
%t f[n_] := Plus @@ Power @@@ FactorInteger[n]; Select[Select[Range[425], PrimeQ[f[ # ]] &], ! PrimeQ[ # ] &] (* _Ray Chandler_, Dec 07 2005 *)
%o (PARI) A008475(n)=local(t);if(n<1,0,t=factor(n);sum(k=1,matsize(t)[1],t[k,1]^t[k,2])); for(i=1,700,if(!isprime(i)&&isprime(A008475(i)),print1(i,","))) (Herrgesell)
%Y Cf. A008475, A114518, A114521, A047820.
%K nonn
%O 1,1
%A _Leroy Quet_, Dec 05 2005
%E Extended by _Ray Chandler_ and Lambert Herrgesell (zero815(AT)googlemail.com), Dec 07 2005
|