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 A323964 #9 Jun 01 2025 19:56:41
%S A323964 0,896,32460,1201920,29987760,705522048,14197154400,264121228800,
%T A323964 4765553385120,80958196300800,1386261729792960,22797317814635520,
%U A323964 378396940680172800,6210934579834490880,101592763596409536000,1694705349980956262400,27653450672540750745600
%N A323964 Number of defective (binary) heaps on n elements with exactly eight defects.
%C A323964 Or number of permutations p of [n] having exactly eight indices i in {1,...,n} such that p(i) > p(floor(i/2)).
%H A323964 Alois P. Heinz, <a href="/A323964/b323964.txt">Table of n, a(n) for n = 8..200</a>
%H A323964 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Heap.html">Heap</a>
%H A323964 Wikipedia, <a href="https://en.wikipedia.org/wiki/Binary_heap">Binary heap</a>
%Y A323964 Column k=8 of A306343.
%Y A323964 Cf. A056971.
%K A323964 nonn
%O A323964 8,2
%A A323964 _Alois P. Heinz_, Feb 09 2019