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%I #34 Sep 08 2022 08:44:50
%S 0,1,2,3,4,6,7,12,13,14,17,34
%N Numbers k such that the decimal expansion of 9^k contains no zeros (probably finite).
%C Integers in A030700 / 2. - _M. F. Hasler_, Mar 07 2014
%C No more terms <= 10^5. - _Georg Fischer_, Mar 12 2020
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Zero.html">Zero</a>
%t Reap[For[n = 0, n < 100, n++, If[FreeQ[IntegerDigits[9^n], 0], Sow[n]]]][[2, 1]] (* _Jean-François Alcover_, Oct 04 2017 *)
%o (PARI) select( is(n)=vecmin(digits(9^n)), [0..39]) \\ _M. F. Hasler_, Mar 07 2014
%o (Magma) [n: n in [0..500] | not 0 in Intseq(9^n)]; // _Vincenzo Librandi_, Mar 08 2014
%Y Cf. A007377 (analog for 2^n), A030700 (3), A030701 (4), A008839 (5), A030702 (6), A030703 and A195908 (7), A030704 (8), A030706 and A195946 (11), A195944 and A195945 (13); A195942, A195943.
%Y This is row 0 of A305929.
%Y Cf. A035064.
%K nonn,base
%O 1,3
%A _Eric W. Weisstein_
%E Offset changed to 1 and initial 0 added by _M. F. Hasler_, Mar 07 2014
%E 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
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