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 A115324 #3 Mar 30 2012 18:36:55 %S A115324 1,1,2,4,9,22,55,141,371,997,2712,7440,20542,57056,159343,447045, %T A115324 1259443,3561529,10119910,28892841,82727805,237322575,681862156, %U A115324 1961930899,5653182325,16312268162,47133250093,136366337701 %N A115324 Central terms of the rows of triangle A115323. %C A115324 Limit a(n+1)/a(n) = 3. %K A115324 nonn %O A115324 0,3 %A A115324 _Paul D. Hanna_, Jan 20 2006