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
KEYWORD
nonn
AUTHOR
Patrick De Geest, Sep 15 1999
STATUS
approved