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 A123788 #7 Jul 21 2017 15:31:49 %S A123788 1,5,53,623,8075,108463,1499542,21128897,302219695,4373563505 %N A123788 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 5 which is flat, i.e., with all blocks in parallel position. %Y A123788 Cf. A112389, A123762 - A123827, A123829 - A123849. %K A123788 nonn,hard %O A123788 1,2 %A A123788 _Søren Eilers_, Oct 29 2006