A050768 Iterated procedure 'composite k added to sum of its prime factors reaches a prime' yields 1 skipped prime.

6, 20, 48, 112, 320, 1326, 1400, 4165, 4374, 10395, 12852, 15827, 20412, 23232, 24300, 24990, 25000, 27200, 27300, 31407, 33660, 34965, 38480, 41553, 42525, 50688, 53508, 65450, 66000, 68400, 69498

Offset: 0

Author

Patrick De Geest, Sep 15 1999

Keywords

• nonn

Examples

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

Crossrefs

Cf. A050703, A050710.

Programs

Mathematica

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