OFFSET
1,4
MATHEMATICA
FromDigits /@ Nest[Append[#, IntegerDigits@ Select[Divisors[FromDigits[Join @@ #]], ! CompositeQ@ # &][[-1]] ] &, {{1}, {1}, {1}}, 7] (* Michael De Vlieger, Nov 26 2018 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
John Mason, Nov 26 2018
EXTENSIONS
a(12) corrected and a(13) added by Daniel Suteu, Jan 19 2019
STATUS
approved