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 A323965 #7 Feb 16 2025 08:33:57
%S A323965 0,3360,190800,6837600,239978112,6268548000,153775564800,
%T A323965 3365570435040,69086614338560,1386261729792960,26344715667079680,
%U A323965 502986050203680000,9251596509192069120,171657357483560256000,3142069546022259916800,57414248711716723200000
%N A323965 Number of defective (binary) heaps on n elements with exactly nine defects.
%C A323965 Or number of permutations p of [n] having exactly nine indices i in {1,...,n} such that p(i) > p(floor(i/2)).
%H A323965 Alois P. Heinz, <a href="/A323965/b323965.txt">Table of n, a(n) for n = 9..200</a>
%H A323965 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Heap.html">Heap</a>
%H A323965 Wikipedia, <a href="https://en.wikipedia.org/wiki/Binary_heap">Binary heap</a>
%Y A323965 Column k=9 of A306343.
%Y A323965 Cf. A056971.
%K A323965 nonn
%O A323965 9,2
%A A323965 _Alois P. Heinz_, Feb 09 2019