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%I #31 Oct 11 2019 16:54:48
%S 2,5,8,11,12,13,14,23,36,38,54,57,59,93,115,119,120,121,136,138,164,
%T 174,176,191,196,212,217,227,233,249
%N Position of rightmost digit 0 in 2^A031140(n).
%C "Positions" are counted 0,1,2,3,... starting with the least significant digit.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Zero.html">Zero.</a>
%t best = 0;
%t x = Select[Range[10000],
%t If[(t = First@
%t First@StringPosition[StringReverse@ToString@(2^#), "0"]) >
%t best, best = t; True] &] ;
%t First /@ First /@
%t StringPosition[StringReverse[ToString /@ (2^x)],
%t "0"] - 1 (* _Robert Price_, Oct 11 2019 *)
%o (PARI) m=0;for(k=0,oo,d=digits(2^k);for(j=0,#d-1,d[#d-j]||(j>m&&print1(m=j,",")||break))) \\ _M. F. Hasler_, Jun 21 2018
%Y Cf. A031140, A031142, A031143.
%K nonn,base,more
%O 1,1
%A _Matthew Cook_, _Dan Hoey_, _Eric W. Weisstein_, _David W. Wilson_
%E More terms from _Dan Hoey_
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