OFFSET
1,1
COMMENTS
I came across this sequence while working some problems in ALCUMUS from the AoPS site. [Tyler]
A 10-automatic set: members are numbers with decimal expansions matching a regular expression. - Charles R Greathouse IV, Feb 20 2012
REFERENCES
MathCounts 2006 National Target #5
MATHEMATICA
Select[3*Range[138], DigitCount[#, 10, 1] > 0 &] (* Alonso del Arte, Feb 20 2012 *)
PROG
(PARI) is(n)=if(n%3, return(0)); n=vecsort(eval(Vec(Str(n))), , 8); n[1]==1||(#n>1&&n[2]==1) \\ Charles R Greathouse IV, Feb 20 2012
(PARI) is(n)=n%3==0 && setsearch(Set(digits(n)), 1) \\ Charles R Greathouse IV, Feb 12 2017
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Seth Tyler, Feb 20 2012
EXTENSIONS
a(7)-a(55) from Charles R Greathouse IV, Feb 20 2012
STATUS
approved