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Position of rightmost 0 (including leading 0) in 2^A031142(n).
5

%I #35 Oct 11 2019 22:45:23

%S 1,2,3,4,5,6,8,9,10,11,12,15,16,21,22,23,24,25,26,36,38,54,57,59,93,

%T 115,119,120,121,136,138,164,174,176,191,196,212,217,227,233,249,250,

%U 260,268,275,308

%N Position of rightmost 0 (including leading 0) in 2^A031142(n).

%C "Positions" are counted 0,1,2,3,... starting with the least significant digit.

%t best = 0; lst = {};

%t x = Select[Range[0, 10000],

%t If[(t = First@

%t First@StringPosition[StringReverse@("0" <> ToString@(2^#)),

%t "0"]) > best, best = t; AppendTo[lst, t - 1]; True] &] ; lst (* _Robert Price_, Oct 11 2019 *)

%Y Cf. A031140, A031141, A031142, A031143.

%K nonn

%O 1,2

%A _Matthew Cook_, _Dan Hoey_, _Eric W. Weisstein_, _David W. Wilson_

%E More terms from _Dan Hoey_

%E a(42)-a(44) from _Alan Griffiths_, Jan 25 2012

%E a(45) from _Alan Griffiths_, Feb 01 2012

%E a(46) from _Alan Griffiths_, Mar 09 2012