%I A080757
%S A080757 1,2,2,1,2,2,2,1,2,2,2,1,2,2,1,2,2,2,1,2,2,2,1,2,2,2,1,2,2,1,2,2,2,1,2,
               2,
%T A080757 2,1,2,2,2,1,2,2,1,2,2,2,1,2,2,2,1,2,2,1,2,2,2,1,2,2,2,1,2,2,2,1,2,2,1,
%U A080757 2,2,2,1,2,2,2,1,2,2,2,1,2,2,1,2,2,2,1,2,2,2,1,2,2,2,1,2,2,1,2,2,2,1,2
%N A080757 First differences of Beatty sequence A022838(n) = floor(n sqrt(3)).
%F A080757 Let S(0) = 1; obtain S(k) from S(k-1) by applying 1 -> 221, 2 -> 2221; 
               sequence is S(0), S(1), S(2), ... - Matthew Vandermast (ghodges14(AT)comcast.net), 
               Mar 25 2003
%t A080757 Flatten[ NestList[ Flatten[ # /. {1 -> {2, 2, 1}, 2 -> {2, 2, 2, 1}}] 
               &, {1}, 4]] (from Robert G. Wilson v (rgwv(AT)rgwv.com), Jun 20 2005)
%Y A080757 Equals A007538(n+1) - 1. Cf. A001030.
%Y A080757 Sequence in context: A085030 A078377 A105697 this_sequence A037196 A116543 
               A107260
%Y A080757 Adjacent sequences: A080754 A080755 A080756 this_sequence A080758 A080759 
               A080760
%K A080757 nonn
%O A080757 0,2
%A A080757 N. J. A. Sloane (njas(AT)research.att.com), Mar 25 2003