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 A348240 #4 Oct 14 2021 18:06:02
%S A348240 1,2,8,26,100
%N A348240 a(n) = Sum_{k = 1..floor(n/2)} A003041(n-2*k).
%H A348240 H. Sharp, Jr., <a href="https://doi.org/10.1016/0012-365X(73)90081-2">Enumeration of vacuously transitive relations</a>, Discrete Math. 4 (1973), 185-196.
%Y A348240 Cf. A003041.
%K A348240 nonn,more
%O A348240 1,2
%A A348240 _N. J. A. Sloane_, Oct 13 2021