OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
filter:= proc(n) local L, v;
L:= convert(n, base, 12);
v:= numboccur(1, L);
v > 0 and v = numboccur(3, L)
end proc:
select(filter, [$1..2000]); # Robert Israel, Dec 31 2019
MATHEMATICA
Select[Range[1100], DigitCount[#, 12, 1]==DigitCount[#, 12, 3]>0&] (* Harvey P. Dale, Apr 21 2011 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved