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 A369336 #16 Jan 22 2024 17:52:01 %S A369336 1,1,12,2052,5684480,305416893750,391129148721673152, %T A369336 14286237711414132094989064,17309880507327972883933887341789184, %U A369336 792117985317303404452447777723478865406570410,1534214120588806182890487155420702132205591283310000000000 %N A369336 Number of n X n Fishburn matrices with entries in the set {0,1,...,n}. %C A369336 Number of upper triangular n X n {0,1,...,n}-matrices with no zero rows or columns. %H A369336 Alois P. Heinz, <a href="/A369336/b369336.txt">Table of n, a(n) for n = 0..35</a> %H A369336 Hsien-Kuei Hwang, Emma Yu Jin, and Michael J. Schlosser, <a href="https://arxiv.org/abs/2012.13570">Asymptotics and statistics on Fishburn Matrices: dimension distribution and a conjecture of Stoimenow</a>, arXiv:2012.13570 [math.CO], 2020. %H A369336 Vít Jelínek, <a href="http://dx.doi.org/10.1016/j.jcta.2011.11.010">Counting general and self-dual interval orders</a>, Journal of Combinatorial Theory, Series A, Volume 119, Issue 3, April 2012, pp. 599-614; <a href="http://arxiv.org/abs/1106.2261">arXiv preprint</a>, arXiv:1106.2261 [math.CO], 2011. %H A369336 Wikipedia, <a href="https://en.wikipedia.org/wiki/Peter_C._Fishburn">Peter C. Fishburn</a> %F A369336 a(n) = [x^n] Sum_{j=0..n} x^j * Product_{i=1..j} ((n+1)^i-1)/(1+x*((n+1)^i-1)). %e A369336 a(0) = 1: []. %e A369336 a(1) = 1: [1]. %e A369336 a(2) = 12: %e A369336 [10] [10] [20] [20] [11] [11] [21] [21] [12] [12] [22] [22] %e A369336 [ 1] [ 2] [ 1] [ 2] [ 1] [ 2] [ 1] [ 2] [ 1] [ 2] [ 1] [ 2]. %p A369336 a:= n-> coeff(series(add(x^j*mul(((n+1)^i-1)/(1+x* %p A369336 ((n+1)^i-1)), i=1..j), j=0..n), x, n+1), x, n): %p A369336 seq(a(n), n=0..10); %Y A369336 Cf. A000007, A005321, A289314, A289315. %Y A369336 Main diagonal of A369415. %K A369336 nonn %O A369336 0,3 %A A369336 _Alois P. Heinz_, Jan 20 2024