OFFSET
1,1
COMMENTS
f(x) = sum of prime factors without multiplicity, so that f(1500) = 2+3+5 = 10.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..2500
MATHEMATICA
bp6Q[n_]:=Length[NestWhileList[Total[FactorInteger[#][[All, 1]]]&, n, CompositeQ[ #]&]]==7; Select[Range[4200], bp6Q] (* Harvey P. Dale, Aug 01 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved