%I #14 Dec 24 2023 18:07:36
%S 1,2,21,2112,21121221,2112122112212112,
%T 21121221122121121221211221121221,
%U 2112122112212112122121122112122112212112211212212112122112212112
%N Successive strings in the construction of the Thue-Morse sequence A001285.
%D A. Salomaa, Jewels of Formal Language Theory. Computer Science Press, Rockville, MD, 1981, p. 6.
%F Drop first half of each word in A080814.
%t Join[{1},Map[FromDigits,SubstitutionSystem[{1->{1,2},2->{2,1}},{2},7]]] (* _Paolo Xausa_, Dec 24 2023 *)
%Y Cf. A080814.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Mar 26 2003
%E a(8) from _Paolo Xausa_, Dec 24 2023