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 A259700 #16 Jun 02 2025 11:53:49
%S A259700 1,3,8,25,72,229,689,2224,6875,22457,70767
%N A259700 a(n) = Sum_{k=2..n-1} k*A259698(n,k).
%C A259700 Sade gives a(5)=25, but that is wrong.
%H A259700 Albert Sade, <a href="/A000108/a000108_17.pdf">Sur les Chevauchements des Permutations</a>, published by the author, Marseille, 1949. [Annotated scanned copy]. See Section 14.
%Y A259700 Cf. A259698, A000682.
%K A259700 nonn,more
%O A259700 2,2
%A A259700 _N. J. A. Sloane_, Jul 05 2015
%E A259700 Corrected and extended by _Roger Ford_, Jul 13 2016