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Complement of A092855.
2

%I #35 Sep 02 2024 08:37:51

%S 1,4,6,8,9,10,11,12,14,15,20,21,24,25,28,29,37,38,42,47,48,51,52,54,

%T 55,57,58,59,60,62,63,64,66,69,70,72,78,81,82,83,85,86,89,92,93,96,

%U 100,102,104,106,107,109,111,113,119,121,122,128,129,130,134,136,139

%N Complement of A092855.

%C Positions of 0 in the binary expansion of sqrt(2) after the radix point. With a prepended 0, A092855 gives the positions of 1.

%H Paolo Xausa, <a href="/A320985/b320985.txt">Table of n, a(n) for n = 1..10000</a>

%e In binary, sqrt(2) is read as 1.0110101000001001111001... The 1st, 4th, 6th and 8th digits after the radix are 0's, so the first four terms are 1, 4, 6 and 8.

%t PositionIndex[First[RealDigits[Sqrt[2], 2, 200, -1]]][0] (* _Paolo Xausa_, Aug 27 2024 *)

%o (PARI) default(realprecision, 150); x=sqrt(2); for(n=1, 150, if(!(floor(x*2^n)%2),print1(n, ", ")))

%o (PARI) Vec(select(x->(x==0), binary(sqrt(2))[2], 1)) \\ _Michel Marcus_, Oct 29 2018

%Y Cf. A004539, A092855.

%K nonn,base

%O 1,2

%A _Jianing Song_, Oct 27 2018