A035058 Numbers k such that 2^k does not contain the digit 3 (probably finite).

0, 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 18, 19, 20, 21, 24, 26, 32, 34, 38, 40, 44, 48, 50, 53, 57, 60, 80, 91, 92, 102, 153

Offset: 1

Author

Patrick De Geest, Nov 15 1998

Keywords

• nonn
• base

Comments

No more terms <= 10^4. - Georg Fischer, Mar 12 2020

Next term > 2*10^5. - Tyler NeSmith, Jul 30 2021

Crossrefs

Cf. similar sequences listed in A035064.

Programs

Magma

[n: n in [0..1000] | not 3 in Intseq(2^n) ]; // Vincenzo Librandi, May 07 2015

Mathematica

Join[{0}, Select[Range@10000, FreeQ[IntegerDigits[2^#], 3] &]] (* Vincenzo Librandi, May 07 2015 *)

PARI

isok(n) = ! vecsearch(Set(digits(2^n)), 3); \\ Michel Marcus, Feb 09 2018

Extensions

Initial 0 added by Vincenzo Librandi, May 07 2015

Removed keyword "fini" as in A035064, since it is only a conjecture that this sequence contains only finitely many terms. - Georg Fischer, Mar 12 2020