A035060 - OEIS

%I #18 Sep 08 2022 08:44:52

%S 0,1,2,3,4,5,6,7,10,11,12,13,14,15,17,18,22,23,24,26,27,30,31,32,34,

%T 36,38,43,46,55,62,65,66,71

%N Numbers k such that 2^k does not contain the digit 5 (probably finite).

%t Join[{0}, Select[Range@10000, FreeQ[IntegerDigits[2^#], 5] &]] (* _Vincenzo Librandi_, May 07 2015 *)

%t Select[Range[0,80],DigitCount[2^#,10,5]==0&] (* _Harvey P. Dale_, Dec 24 2018 *)

%o (Magma) [n: n in [0..1000] | not 5 in Intseq(2^n) ]; // _Vincenzo Librandi_, May 07 2015

%Y Cf. similar sequences listed in A035064.

%K nonn,base

%O 1,3

%A _Patrick De Geest_, Nov 15 1998

%E Initial 0 inserted by _Vincenzo Librandi_, May 07 2015