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 A334777 #9 May 20 2020 02:55:20
%S A334777 1,9,195,7140,396900,31185000,3291888600,449513064000,77111922888000,
%T A334777 16235185926960000,4116213602701200000,1237059394731800640000,
%U A334777 434864246413372776000000,176784623645708110032000000,82297894534015170170160000000,43496460979945066988294400000000
%N A334777 Total number of local maxima in all permutations of 2 indistinguishable copies of 1..n.
%H A334777 Andrew Howroyd, <a href="/A334777/b334777.txt">Table of n, a(n) for n = 1..100</a>
%F A334777 a(n) = Sum_{k=1..n} k*A334774(n,k).
%F A334777 a(n) = A334776(n) + A000680(n).
%o A334777 (PARI) \\ PeaksBySig defined in A334774.
%o A334777 a(n)={my(u=PeaksBySig(vector(n,i,2), [0..n-1])); sum(k=1, #u, k*u[k])}
%Y A334777 Cf. A000680, A334774, A334775, A334776.
%K A334777 nonn
%O A334777 1,2
%A A334777 _Andrew Howroyd_, May 12 2020