OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Multiplicative Digital Root
MATHEMATICA
mdr6Q[n_]:=NestWhile[Times@@IntegerDigits[#]&, n, #>9&]==6; Select[Range[400], mdr6Q] (* Harvey P. Dale, Jul 14 2024 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Patrick De Geest, Sep 15 1998
STATUS
approved