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 A324067 #7 Feb 16 2025 08:33:57
%S A324067 0,0,0,0,0,8,100,720,5040,36736,268800,2073600,17186400,147502080,
%T A324067 1331616000,13047091200,110053944000,1011903692800,9874978713600,
%U A324067 106953080832000,1086116967936000,12275238666240000,144074916311040000,1890064025321472000
%N A324067 Number of defective (binary) heaps on n elements where six ancestor-successor pairs do not have the correct order.
%C A324067 Or number of permutations p of [n] having exactly six pairs (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).
%H A324067 Alois P. Heinz, <a href="/A324067/b324067.txt">Table of n, a(n) for n = 0..200</a>
%H A324067 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Heap.html">Heap</a>
%H A324067 Wikipedia, <a href="https://en.wikipedia.org/wiki/Binary_heap">Binary heap</a>
%H A324067 Wikipedia, <a href="https://en.wikipedia.org/wiki/Permutation">Permutation</a>
%Y A324067 Column k=6 of A306393.
%Y A324067 Cf. A056971.
%K A324067 nonn
%O A324067 0,6
%A A324067 _Alois P. Heinz_, Feb 13 2019