|
%I #20 Oct 13 2023 14:02:59
%S 1,3,9,11,25,27,73,75,89,91,201,203,217,219,585,587,601,603,713,715,
%T 729,731,1609,1611,1625,1627,1737,1739,1753,1755,4681,4683,4697,4699,
%U 4809,4811,4825,4827,5705,5707,5721,5723,5833,5835
%N Numbers whose set of base-8 digits is {1,3}.
%H Vincenzo Librandi, <a href="/A032915/b032915.txt">Table of n, a(n) for n = 1..1000</a>
%t Flatten[Table[FromDigits[#,8]&/@Tuples[{1,3},n],{n,5}]] (* _Vincenzo Librandi_, Jun 01 2012 *)
%o (Magma) [n: n in [1..6000] | Set(IntegerToSequence(n, 8)) subset {1, 3}]; // _Vincenzo Librandi_, Jun 01 2012
%o (Python)
%o 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 Cf. A007094, A032917.
%K nonn,base
%O 1,2
%A _Clark Kimberling_
|
