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 A114178 #3 Mar 30 2012 18:36:52 %S A114178 1,3,18,135,1083,9219,80631,724080,6601639,61065270,570430258, %T A114178 5376309654,51020229343,487127706521,4674459993450,45056351087502, %U A114178 435965482847738,4232871507349381,41222355832803426,402540756184423291 %N A114178 Central terms of triangle A114176 found in even-indexed rows. %Y A114178 Cf. A114176, A114177 (row sums), A114179 (row sums-square). %K A114178 nonn %O A114178 0,2 %A A114178 _Paul D. Hanna_, Nov 15 2005