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 A323966 #7 Feb 16 2025 08:33:57
%S A323966 0,19200,947760,49680576,1744142400,60169824000,1646888944800,
%T A323966 42633973724160,1013373907056960,22797317814635520,502986050203680000,
%U A323966 10556482426015426560,222685725334400064000,4535040919258899456000,92995172484979478630400,1880492299058130490163200
%N A323966 Number of defective (binary) heaps on n elements with exactly ten defects.
%C A323966 Or number of permutations p of [n] having exactly ten indices i in {1,...,n} such that p(i) > p(floor(i/2)).
%H A323966 Alois P. Heinz, <a href="/A323966/b323966.txt">Table of n, a(n) for n = 10..200</a>
%H A323966 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Heap.html">Heap</a>
%H A323966 Wikipedia, <a href="https://en.wikipedia.org/wiki/Binary_heap">Binary heap</a>
%Y A323966 Column k=10 of A306343.
%Y A323966 Cf. A056971.
%K A323966 nonn
%O A323966 10,2
%A A323966 _Alois P. Heinz_, Feb 09 2019