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 A336525 #18 Jul 27 2020 16:32:38 %S A336525 1,1,3,14,96,895,11751,214708,5594463 %N A336525 Total number of linear extensions of all n-element posets. %C A336525 Sum of e(P) over all nonisomorphic n-element posets, where e(P) is the number of linear extensions of P. %e A336525 There is one 3-element poset with 6 linear extensions, one with 3, two with 2, and one with 1, for a total of 14. %Y A336525 Cf. A006251, A080687, A248091, A301871, A336229, A006455. %K A336525 nonn,more %O A336525 0,3 %A A336525 _Richard Stanley_, Jul 27 2020