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 A243420 #4 Jun 04 2014 18:01:58 %S A243420 1,19,229,2184,17759,128509,851831,5278129,31020976,174803309, %T A243420 952033480,5042006351,26087126992,132340281386,660143136637, %U A243420 3245280843311,15751929981822,75602686035094,359256881535197,1691965976395069,7904617778358794,36660673151053000 %N A243420 Number of Dyck paths of semilength n having exactly 8 (possibly overlapping) occurrences of the consecutive steps UDUUDU (with U=(1,1), D=(1,-1)). %H A243420 Alois P. Heinz, <a href="/A243420/b243420.txt">Table of n, a(n) for n = 18..550</a> %Y A243420 Column k=8 of A243366. %K A243420 nonn %O A243420 18,2 %A A243420 _Alois P. Heinz_, Jun 04 2014