This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A246105 #6 Jan 10 2024 16:02:25
%S A246105 2,1,3,2,1,5,4,3,2,1,8,7,6,5,4,3,2,1,13,12,11,10,9,8,7,6,5,4,3,2,1,21,
%T A246105 20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,34,33,32,31,30,29,
%U A246105 28,27,26,25,24,23,22,21,20,19,18,17,16,15,14,13
%N A246105 Least m > 0 for which (s(m),...,s(n+m-1)) = (s(n),...,s(0)), the reverse of the first n+1 terms of the infinite Fibonacci word A003849.
%F A246105 Concatenation of blocks (F(k), F(k - 1), ..., F(3), F(2)) beginning with k = 3, where F = A000045 (Fibonacci numbers).
%e A246105 reverse(s(0),...,s(6)) = reverse(0,1,0,0,1,0,1) = (1,0,1,0,0,1,0)
%e A246105 first repeats in A003849 at (s(4),...,s(10)), so that a(6) = 4.
%t A246105 s = Flatten[Nest[{#, #[[1]]} &, {0, 1}, 12]]; b[m_, n_] := b[m, n] = Take[s, {m, n}]; t = -1 + Flatten[Table[Select[Range[2, 1600], b[#, n + # - 1] == Reverse[b[1, n]] &, 1], {n, 1, 120}]]
%Y A246105 Cf. A003849, A000045, A246104, A241422.
%K A246105 nonn,easy
%O A246105 0,1
%A A246105 _Clark Kimberling_, Aug 14 2014