Search: id:A122497 Results 1-1 of 1 results found. %I A122497 %S A122497 1,2,1,1,2,2,1,2,1,1,2,1,2,2,1,1,2,2,1,2,1,1,2,2,1,1,2,1,2,2,1,2,1,1,2, %T A122497 1,2,2,1,1,2,2,1,2,1,1,2,1,2,2,1,2,1,1,2,2,1,1,2,1,2,2,1,1,2,2,1,2,1,1, %U A122497 2,2,1,1,2,1,2,2,1,2,1,1,2,1,2,2,1,1,2,2,1,2,1,1,2,2,1,1,2,1,2,2,1,1,2 %N A122497 Let f(S) denote the interchange of 1's and 2's in S. Let S_0 = 1, S_{N+1} = f(S_N).S_N, where the dot indicates concatenation. Sequence gives S_0.S_1.S_2.S_3.... %C A122497 An alternating triangular Morse -Thue sequence based on A010060 using {1,2} instead of {0,1} substitutions. %H A122497 Eric Weisstein's World of Mathematics, Thue-Morse Constant %F A122497 1->)1,2} 2->{2,1} a(n) = ThueMorse[n, 1 + Mod[n, 2]] %e A122497 The first few S_i are: %e A122497 1 %e A122497 2, 1 %e A122497 1, 2, 2, 1 %e A122497 2, 1, 1, 2, 1, 2, 2, 1 %e A122497 1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 1, 2, 1, 2, 2, 1 %t A122497 ThueMorse[n_, b_] := Nest[Flatten[ # /. {1 -> {1, 2}, 2 -> {2, 1}}] &, {b}, n] a = Table[ThueMorse[n, 1 + Mod[n, 2]], {n, 0, 7}] Flatten[a] %Y A122497 Cf. A010060, A014571, A014572, A074072, A074073. %Y A122497 Sequence in context: A049705 A060236 A006345 this_sequence A154402 A023396 A091221 %Y A122497 Adjacent sequences: A122494 A122495 A122496 this_sequence A122498 A122499 A122500 %K A122497 nonn %O A122497 1,2 %A A122497 Roger Bagula (rlbagulatftn(AT)yahoo.com), Sep 15 2006 %E A122497 Edited by N. J. A. Sloane (njas(AT)research.att.com), May 22 2007 Search completed in 0.001 seconds