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 A118077 #28 Apr 02 2025 18:22:24
%S A118077 1,2,6,32,454,35512,66584412,36566354210304
%N A118077 Number of edges in the representation of all linear extensions of the inclusion ordering on P({1,...,n}) as distributive lattice contained in P(P({1,...,n})).
%C A118077 The numbers of vertices are the Dedekind numbers (A000372) and A046873 is the total number of linear extensions.
%F A118077 a(n) = Sum_{m=1..C(n,floor(n/2))} A059119(n,m)*m. - _Geoffrey Critzer_, Aug 11 2020
%e A118077 a(2) = 6 as the lattice is { {}, { {} }, { {}, {1} }, { {}, {2} }, { {}, {1}, {2}}, { {}, {1}, {2}, {1, 2} } }.
%Y A118077 Cf. A046873, A000372, A059119.
%K A118077 nonn,hard,more
%O A118077 0,2
%A A118077 _Oliver Wienand_, Apr 11 2006
%E A118077 a(7) added by _Geoffrey Critzer_, Aug 11 2020 from A059119
%E A118077 a(7) corrected by _Lennart Van Hirtum_, Apr 02 2025