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A050768
Iterated procedure 'composite k added to sum of its prime factors reaches a prime' yields 1 skipped prime.
1
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
0,1
EXAMPLE
a(2)=20 + (2+2+5) = ending prime 29. Between 20 and 29 lies exactly one prime 23.
MATHEMATICA
aQ[n_]:=NextPrime[NestWhile[#+Total[Times@@@FactorInteger[#]]&, n, !PrimeQ[#]&], -1]==NextPrime[n]; Select[Range[70000], !PrimeQ[#]&&aQ[#]&] (* Jayanta Basu, May 31 2013 *)
CROSSREFS
Sequence in context: A055455 A203552 A331754 * A161438 A063488 A299292
KEYWORD
nonn
AUTHOR
Patrick De Geest, Sep 15 1999
STATUS
approved