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!)
A308173 Take the list of all binary vectors (including those beginning with 0) in lexicographic order; a(n) is the index of the first occurrence of the n-th binary vector as a subsequence of A038219. 2

%I #19 May 21 2019 11:54:51

%S 1,2,3,1,2,5,13,3,1,4,2,6,5,10,17,13,14,3,1,7,4,9,12,2,6,8,11,5,10,21,

%T 48,17,13,18,14,28,3,19,15,1,29,7,25,4,9,20,16,12,27,2,30,6,24,8,11,

%U 26,5,23,10,22,21,58,99,48,49,17,13,50,43,18,14,33,28

%N Take the list of all binary vectors (including those beginning with 0) in lexicographic order; a(n) is the index of the first occurrence of the n-th binary vector as a subsequence of A038219.

%C Ehrenfeucht and Mycielski (1992) prove that every binary vector appears in A038219, so the sequence is well-defined.

%H Rémy Sigrist, <a href="/A308173/b308173.txt">Table of n, a(n) for n = 1..65535</a>

%H A. Ehrenfeucht and J. Mycielski, <a href="http://www.jstor.org/stable/2324917">A pseudorandom sequence - how random is it?</a>, Amer. Math. Monthly, 99 (1992), 373-375.

%e A038219 begins 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, ... and has offset 1. Here is the start of the list of binary vectors and the index where they first appear in the sequence:

%e 0: 1

%e 1: 2

%e 00: 3

%e 01: 1

%e 10: 2

%e 11: 5

%e 000: 13

%e 001: 3

%e ...

%Y Cf. A038219, A253060, A253061.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, May 20 2019

%E More terms from _Rémy Sigrist_, May 21 2019

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 March 28 16:58 EDT 2024. Contains 371254 sequences. (Running on oeis4.)