%I A006340 M0100
%S A006340 2,1,2,1,2,2,1,2,2,1,2,1,2,2,1,2,2,1,2,1,2,2,1,2,1,2,2,1,2,2,1,
%T A006340 2,1,2,2,1,2,1,2,2,1,2,2,1,2,1,2,2,1,2,2,1,2,1,2,2,1,2,1,2,2,1,
%U A006340 2,2,1,2,1,2,2,1,2,1,2,2,1,2,2,1,2,1,2,2,1,2,2,1,2,1,2,2,1,2,1
%N A006340 An "eta-sequence": [ (n+1)*tau + 1/2 ] - [ n*tau + 1/2 ], tau =(1+ sqrt 
               5)/2.
%C A006340 Equals its own "derivative", which is formed by counting the strings 
               of 1's that lie between 2's.
%D A006340 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%H A006340 T. D. Noe, <a href="b006340.txt">Table of n, a(n) for n=0..1000</a>
%Y A006340 Differs from A014675 in many places.
%Y A006340 Sequence in context: A080763 A165413 A080573 this_sequence A076371 A106149 
               A054740
%Y A006340 Adjacent sequences: A006337 A006338 A006339 this_sequence A006341 A006342 
               A006343
%K A006340 nonn,easy,nice
%O A006340 0,1
%A A006340 D. R. Hofstadter
%E A006340 Extended by N. J. A. Sloane (njas(AT)research.att.com), Nov 07, 2001