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 A035064 #30 Jul 10 2025 11:04:07
%S A035064 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 A035064 31,45,46,47,57,58,59,71,77,99,108
%N A035064 Numbers k such that 2^k does not contain the digit 9 (probably finite).
%e A035064 Here is 2^108, conjecturally the largest power of 2 that does not contain a 9: 324518553658426726783156020576256. - _N. J. A. Sloane_, Feb 10 2023
%t A035064 Join[{0}, Select[Range@ 1000, FreeQ[IntegerDigits[2^#], 9] &]] (* _Vincenzo Librandi_, May 06 2015 *)
%o A035064 (Magma) [n: n in [0..1000] | not 9 in Intseq(2^n) ]; // _Vincenzo Librandi_, May 06 2015
%o A035064 (PARI) A035064 = select( is_A035064(n)=vecmax(digits(2^n))<9, [0..199]) \\ _M. F. Hasler_, Jul 09 2025
%o A035064 (Python) (A035064:=[n for n in range(123) if max(str(2**n))<'9']) # _M. F. Hasler_, Jul 09 2025
%Y A035064 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).
%Y A035064 Indices of zeros in A065744 (number of 9s in digits of 2^n).
%K A035064 nonn,base
%O A035064 1,3
%A A035064 _Patrick De Geest_, Nov 15 1998
%E A035064 Initial 0 added by _Vincenzo Librandi_, May 06 2015
%E A035064 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