OFFSET
1,1
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..700
FORMULA
a(n) = 7*A043310(n) (= 7*n for n<6). - M. F. Hasler, Feb 02 2014
MATHEMATICA
Select[Range[10000], Union[Length/@Split[IntegerDigits[#, 6]]]=={2}&] (* Vincenzo Librandi, Feb 05 2014 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved