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 A089506 #16 Mar 15 2018 04:23:10
%S A089506 1,3,27,513,540702,8891844390,27306854121690,94235953573952190,
%T A089506 1684561906087969348440,1106757172299795861925080,
%U A089506 8644064410182787098480243878401800,289900692457541891469406183557646377576408600,1206267931807293851480420134690207296382114287151076400
%N A089506 Denominators used in A089505 to compute column sequences of triangle A089504.
%H A089506 Vincenzo Librandi, <a href="/A089506/b089506.txt">Table of n, a(n) for n = 1..50</a>
%F A089506 a(n) = lcm(seq(denominator(a(n, m)), m=1..n)) with the a(n, m) formula given in A089505(n, m) but without the D(n) factor in front and lcm denotes the least common multiple of a set of numbers.
%t A089506 a[n_, m_] := (-1)^(n-m)*FactorialPower[m+2, 3]^(n-1)/(Product[ FactorialPower[m+2, 3] - FactorialPower[r+2, 3], {r, 1, m-1}]*Product[ FactorialPower[r+2, 3] - FactorialPower[m+2, 3], {r, m+1, n}]); a[n_] := LCM @@ Table[Denominator[a[n, m]], {m, 1, n}]; Array[a, 11] (* _Jean-François Alcover_, Sep 02 2016 *)
%K A089506 nonn,easy
%O A089506 1,2
%A A089506 _Wolfdieter Lang_, Dec 01 2003
%E A089506 a(12)-a(13) from _Vincenzo Librandi_, Mar 15 2018