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 A027680 #12 Nov 21 2019 07:39:31 %S A027680 2,13,55447,1621477990380993035885 %N A027680 Number of independent subsets of 5^n cube (P_5 X ... X P_5). %e A027680 For n=0, the two sets are the empty set and a set containing a single isolated vertex. - _Sean A. Irvine_, Nov 20 2019 %Y A027680 Cf. A027624, A027667, A027668. %K A027680 nonn,hard,more %O A027680 0,1 %A A027680 _R. H. Hardin_ %E A027680 a(0) corrected by _Sean A. Irvine_, Nov 20 2019