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 A323963 #7 Feb 16 2025 08:33:57
%S A323963 0,210,7616,185460,4200960,77887920,1310267904,21025461600,
%T A323963 314958758400,4765553385120,69086614338560,1013373907056960,
%U A323963 14714554645140480,212868974122848000,3168605413206097920,45787509175434048000,705241846739554713600,10297540417675899801600
%N A323963 Number of defective (binary) heaps on n elements with exactly seven defects.
%C A323963 Or number of permutations p of [n] having exactly seven indices i in {1,...,n} such that p(i) > p(floor(i/2)).
%H A323963 Alois P. Heinz, <a href="/A323963/b323963.txt">Table of n, a(n) for n = 7..200</a>
%H A323963 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Heap.html">Heap</a>
%H A323963 Wikipedia, <a href="https://en.wikipedia.org/wiki/Binary_heap">Binary heap</a>
%Y A323963 Column k=7 of A306343.
%Y A323963 Cf. A056971.
%K A323963 nonn
%O A323963 7,2
%A A323963 _Alois P. Heinz_, Feb 09 2019