This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A032915 #20 Oct 13 2023 14:02:59 %S A032915 1,3,9,11,25,27,73,75,89,91,201,203,217,219,585,587,601,603,713,715, %T A032915 729,731,1609,1611,1625,1627,1737,1739,1753,1755,4681,4683,4697,4699, %U A032915 4809,4811,4825,4827,5705,5707,5721,5723,5833,5835 %N A032915 Numbers whose set of base-8 digits is {1,3}. %H A032915 Vincenzo Librandi, <a href="/A032915/b032915.txt">Table of n, a(n) for n = 1..1000</a> %t A032915 Flatten[Table[FromDigits[#,8]&/@Tuples[{1,3},n],{n,5}]] (* _Vincenzo Librandi_, Jun 01 2012 *) %o A032915 (Magma) [n: n in [1..6000] | Set(IntegerToSequence(n, 8)) subset {1, 3}]; // _Vincenzo Librandi_, Jun 01 2012 %o A032915 (Python) %o A032915 def A032915(n): return (int(bin(m:=n+1)[3:],8)<<1) + ((1<<3*(m.bit_length()-1))-1)//7 # _Chai Wah Wu_, Oct 13 2023 %Y A032915 Cf. A007094, A032917. %K A032915 nonn,base %O A032915 1,2 %A A032915 _Clark Kimberling_