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 A083932 #10 Jan 30 2024 08:23:22 %S A083932 0,12,204,240,3276,3312,3852,3888,4032,52428,52464,53004,53040,53184, %T A083932 61644,61680,62220,62256,62400,64524,64560,64704,65280,838860,838896, %U A083932 839436,839472,839616,848076,848112,848652,848688,848832,850956,850992 %N A083932 A014486-encoding of the Catalan mountain ranges with only even-length slopes allowed. %C A083932 Subset of totally balanced binary strings (A014486) with only even runs of either bit 0 or 1 occurring. See A083933. %H A083932 <a href="/index/Ro#RootedTreePlanEncodings">Index entries for encodings of plane rooted trees</a> %F A083932 a(n) = A008585(A083931(n)), i.e. 3*A083931(n). %Y A083932 Same sequence in binary: A083933, indices to A014486: A083934. %Y A083932 Permutation of A080316 from which this differs first time at the sixth term, with a(6)=3852, while A080316(6)=4032. %K A083932 nonn %O A083932 0,2 %A A083932 _Antti Karttunen_, May 13 2003