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 A324071 #7 Feb 16 2025 08:33:57
%S A324071 0,0,0,0,0,0,0,80,3150,36736,359520,3532800,36115200,383708160,
%T A324071 4247443200,48673996800,515675160000,5654852403200,64785924403200,
%U A324071 788119068672000,9695238119424000,125961866477568000,1700829800017920000,24580421999198208000
%N A324071 Number of defective (binary) heaps on n elements where ten ancestor-successor pairs do not have the correct order.
%C A324071 Or number of permutations p of [n] having exactly ten pairs (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).
%H A324071 Alois P. Heinz, <a href="/A324071/b324071.txt">Table of n, a(n) for n = 0..200</a>
%H A324071 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Heap.html">Heap</a>
%H A324071 Wikipedia, <a href="https://en.wikipedia.org/wiki/Binary_heap">Binary heap</a>
%H A324071 Wikipedia, <a href="https://en.wikipedia.org/wiki/Permutation">Permutation</a>
%Y A324071 Column k=10 of A306393.
%Y A324071 Cf. A056971.
%K A324071 nonn
%O A324071 0,8
%A A324071 _Alois P. Heinz_, Feb 13 2019