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%I #18 Aug 02 2022 17:29:55
%S 1,4,8,9,14,15,16,18,20,21,24,25,26,27,30,32,33,35,36,38,39,42,44,46,
%T 49,50,51,55,57,60,62,64,65,66,68,69,70,72,74,77,78,81,84,85,86,87,91,
%U 92,93,94,95,98,100,102,105,106,110,111,112,114,115,116,119,120,121,122
%N Numbers whose sum of prime factors (counted with multiplicity) is not prime.
%C The first term is 1, since 1 has no prime factors and so the sum of prime factors evaluates to zero.
%C Conjecture: a(n) ~ n. - _Charles R Greathouse IV_, Apr 28 2015
%H Hieronymus Fischer, <a href="/A134376/b134376.txt">Table of n, a(n) for n = 1..10000</a>
%e a(2) = 4, since 4 = 2*2 and 2+2 = 4 is not prime.
%e a(5) = 14, since 14 = 2*7 and 2+7 = 9 is not prime.
%t Select[Range[150],!PrimeQ[Total[Flatten[Table[#[[1]],#[[2]]]&/@ FactorInteger[ #]]]]&] (* _Harvey P. Dale_, Jul 05 2021 *)
%o (PARI) sopfr(n)=my(f=factor(n)); sum(i=1,#f~,f[i,1]*f[i,2])
%o is(n)=!isprime(sopfr(n)) \\ _Charles R Greathouse IV_, Apr 28 2015
%Y Cf. A000040, A001222, A100118, A046363, A133620, A133621, A133880, A133890, A133900, A133910, A133911, A046346, A134331, A134332, A134333, A134334, A134344, A078177.
%K nonn
%O 1,2
%A _Hieronymus Fischer_, Oct 23 2007
%E Edited by the author at the suggestion of _T. D. Noe_, May 20 2013
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