# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a261415
Showing 1-1 of 1

%I A261415 #15 Jul 25 2017 01:20:07
%S A261415 0,1,3,7,8,10,21,22,24,49,50,52,56,57,59,70,71,73,147,148,150,154,155,
%T A261415 157,168,169,171,343,344,346,350,351,353,364,365,367,392,393,395,399,
%U A261415 400,402,413,414,416,490,491,493,497,498,500,511,512,514
%N A261415 The maximal midpoint-free set Z_7^{+}{0,1,3}.
%C A261415 The sequence consists of the numbers that expressed in base 7 contain only the digits 0, 1 and 3. - _Giovanni Resta_, Aug 26 2015
%H A261415 Roger B. Eggleton, <a href="http://dx.doi.org/10.1155/2015/216475">Maximal Midpoint-Free Subsets of Integers</a>, International Journal of Combinatorics, Volume 2015, Article ID 216475, 14 pages.
%H A261415 <a href="/index/Ar#7-automatic">Index entries for 7-automatic sequences</a>.
%t A261415 Select[Range[0, 1000], Union[ IntegerDigits[#, 7], {0, 1, 3}] == {0, 1, 3} &] (* _Giovanni Resta_, Aug 26 2015 *)
%o A261415 (PARI) is(n)=#setunion(Set(digits(n,7)),[0,1,3])==3 \\ _Charles R Greathouse IV_, Feb 15 2017
%K A261415 nonn,base,easy
%O A261415 1,3
%A A261415 _N. J. A. Sloane_, Aug 25 2015
%E A261415 More terms from _Giovanni Resta_, Aug 26 2015

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE