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%I #16 Feb 10 2023 16:52:32
%S 0,1,2,3,4,5,6,7,8,9,10,11,14,15,16,17,18,19,20,23,24,25,26,27,28,30,
%T 31,45,46,47,57,58,59,71,77,99,108
%N Numbers n such that 2^n does not contain the digit 9 (probably finite).
%e Here is 2^108, conjecturally the largest power of 2 that does not contain a 9:
%e 324518553658426726783156020576256. - _N. J. A. Sloane_, Feb 10 2023
%t Join[{0}, Select[Range@ 1000, FreeQ[IntegerDigits[2^#], 9] &]] (* _Vincenzo Librandi_, May 06 2015 *)
%o (Magma) [n: n in [0..1000] | not 9 in Intseq(2^n) ]; // _Vincenzo Librandi_, May 06 2015
%Y Cf. numbers n such that decimal expansion of 2^n contains no k: A007377 (k=0), A035057 (k=1), A034293 (k=2), A035058 (k=3), A035059 (k=4), A035060 (k=5), A035061 (k=6), A035062 (k=7), A035063 (k=8), this sequence (k=9).
%K nonn,base
%O 1,3
%A _Patrick De Geest_, Nov 15 1998
%E Initial 0 added by _Vincenzo Librandi_, May 06 2015
%E Removed keyword "fini" at the suggestion of _Nathan Fox_, since it is only a conjecture that this sequence contains only finitely many terms. - _N. J. A. Sloane_, Mar 03 2016
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