login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A293763 Numbers k such that (d(k), d(k+1)) = (1,0) in the base-2 digits d(i) of sqrt(2). 4

%I #8 Dec 10 2023 17:12:20

%S 1,4,6,8,14,20,24,28,37,42,47,51,54,57,62,66,69,72,78,81,85,89,92,96,

%T 100,102,104,106,109,111,113,119,121,128,134,136,139,144,147,153,157,

%U 159,161,165,168,173,177,179,181,186,190,195,198,200,204,209,211

%N Numbers k such that (d(k), d(k+1)) = (1,0) in the base-2 digits d(i) of sqrt(2).

%C This sequence together with A293761, A293762, and A293764 partition the positive integers.

%H Clark Kimberling, <a href="/A293763/b293763.txt">Table of n, a(n) for n = 1..10000</a>

%e (d(i)) = (1,0,1,1,0,1,0,1,0,0,0,0,0,1,...) = A004539, in which (0,1) first occurs as (a(1),a(2)).

%t z = 100; s = StringJoin[Map[ToString, First[RealDigits[N[Sqrt[2], 10000], 2]]]];

%t Take[Map[#[[1]]&,StringPosition[s,"00"]],z] (*A293761*)

%t Take[Map[#[[1]]&,StringPosition[s,"01"]],z] (*A293762*)

%t Take[Map[#[[1]]&,StringPosition[s,"10"]],z] (*A293763*)

%t Take[Map[#[[1]]&,StringPosition[s,"11"]],z] (*A293764*)

%t (* _Peter J. C. Moses_, Oct 15 2017 *)

%t SequencePosition[RealDigits[Sqrt[2],2,250][[1]],{1,0}][[;;,1]] (* _Harvey P. Dale_, Dec 10 2023 *)

%Y Cf. A004539, A293761, A293762, A293764.

%K nonn,easy,base

%O 1,2

%A _Clark Kimberling_, Oct 19 2017

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 15:18 EDT 2024. Contains 371960 sequences. (Running on oeis4.)