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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..30.

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

Cf. A050703, A050710.

Sequence in context: A011928 A055455 A203552 * A161438 A063488 A299292

Adjacent sequences:  A050765 A050766 A050767 * A050769 A050770 A050771

KEYWORD

nonn

AUTHOR

Patrick De Geest, Sep 15 1999.

STATUS

approved

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Last modified February 22 19:27 EST 2018. Contains 299469 sequences. (Running on oeis4.)