A050768 - OEIS

%I #8 Oct 17 2019 22:44:53

%S 6,20,48,112,320,1326,1400,4165,4374,10395,12852,15827,20412,23232,

%T 24300,24990,25000,27200,27300,31407,33660,34965,38480,41553,42525,

%U 50688,53508,65450,66000,68400,69498

%N Iterated procedure 'composite k added to sum of its prime factors reaches a prime' yields 1 skipped prime.

%e a(2)=20 + (2+2+5) = ending prime 29. Between 20 and 29 lies exactly one prime 23.

%t aQ[n_]:=NextPrime[NestWhile[#+Total[Times@@@FactorInteger[#]]&,n,!PrimeQ[#]&],-1]==NextPrime[n]; Select[Range[70000],!PrimeQ[#]&&aQ[#]&] (* _Jayanta Basu_, May 31 2013 *)

%Y Cf. A050703, A050710.

%K nonn

%O 0,1

%A _Patrick De Geest_, Sep 15 1999