Search: id:A088569 Results 1-1 of 1 results found. %I A088569 %S A088569 1,1,2,2,1,2,1,1,2,1,1,2,2,1,2,2,1,1,2,1,2,2,1,2,1,1,2,2,1,2,2,1,2,1,1, %T A088569 2,1,1,2,2,1,2,1,1,2,1,2,2,1,2,2,1,1,2,1,1,2,2,1,2,1,1,2,1,1,2,2,1,2,2, %U A088569 1,2,1,1,2,1,2,2,1,1,2,1,1,2,2,1,2,1,1,2,1,1,2,2,1,2,2,1,1,2,1,2,2,1,2 %N A088569 Anti-Kolakoski sequence (sequence of length runs never coincides with the sequence itself). %C A088569 Unique infinite word defined on alphabet {1,2} satisfying: a(1)=1, if a(n)=2 length of n-th run is 1, if a(n)=1 length of n-th run is 2. Kolakoski sequence satisfies the opposite definition : K(1)=1, if K(n)=2 length of n-th run is 2, if K(n)=1 length of n-th run is 1. %F A088569 a(n)=3-A000002(n+1)=A049705(n+1) %e A088569 a(1)=1 hence first run must have length 2 and necessarily a(2)=1. Now second run must have also length 2 and therefore a(3)=a(4)=2. %Y A088569 Sequence in context: A164295 A035214 A071292 this_sequence A001285 A088424 A097456 %Y A088569 Adjacent sequences: A088566 A088567 A088568 this_sequence A088570 A088571 A088572 %K A088569 nonn %O A088569 1,3 %A A088569 Benoit Cloitre (benoit7848c(AT)orange.fr), Nov 17 2003 Search completed in 0.001 seconds