OFFSET
1,3
COMMENTS
The sequence consists of the numbers that expressed in base 7 contain only the digits 0, 1 and 3. - Giovanni Resta, Aug 26 2015
LINKS
Roger B. Eggleton, Maximal Midpoint-Free Subsets of Integers, International Journal of Combinatorics, Volume 2015, Article ID 216475, 14 pages.
MATHEMATICA
Select[Range[0, 1000], Union[ IntegerDigits[#, 7], {0, 1, 3}] == {0, 1, 3} &] (* Giovanni Resta, Aug 26 2015 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
N. J. A. Sloane, Aug 25 2015
EXTENSIONS
More terms from Giovanni Resta, Aug 26 2015
STATUS
editing