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 A057543 #14 Jun 13 2022 16:46:52 %S A057543 1,1,2,3,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46, %T A057543 48,50,52,54,56,58,60,62,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92, %U A057543 94,96,98,100,102,104,106,108,110,112,114,116,118,120,122,124 %N A057543 Maximum cycle length (orbit size) in the rotation permutation of 2n non-crossing handshakes. %C A057543 That is, in permutations A057501 and A057502, the longest cycle among all cycles between the (A014138(n-2)+1)th and (A014138(n-1))th terms. %F A057543 a(0)=1, a(1)=1, a(2)=2, a(3)=3, and a(n)=2*n for n>=4. %Y A057543 Cf. A057542, A057544, A057545. %K A057543 nonn %O A057543 0,3 %A A057543 _Antti Karttunen_, Sep 07 2000 %E A057543 More terms from _Sean A. Irvine_, Jun 13 2022