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 A123778 #7 Feb 15 2025 15:24:15 %S A123778 1,12,425,17610,818803,40408828,2078794759,110210311068 %N A123778 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 4. %Y A123778 Cf. A112389, A123762 - A123827, A123829 - A123849. %K A123778 nonn,hard %O A123778 1,2 %A A123778 _Søren Eilers_, Oct 29 2006