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 A218106 #13 Aug 02 2021 08:25:26
%S A218106 0,1,80963,25188019,1913052805,84934607175,3085918099231,
%T A218106 104970367609107,3527548086703069,119752042470064290,
%U A218106 4150321205365373610,147666165472551221730,5409628424337030402002,204363410596110256258446,7966805463258438079563650
%N A218106 Number of transitive reflexive early confluent binary relations R on n+6 labeled elements with max_{x}(|{y : xRy}|) = n.
%C A218106 R is early confluent iff (xRy and xRz) implies (yRz or zRy) for all x, y, z.
%H A218106 Alois P. Heinz, <a href="/A218106/b218106.txt">Table of n, a(n) for n = 0..200</a>
%F A218106 a(n) = A135313(n+6,n).
%p A218106 t:= proc(k) option remember; `if` (k<0, 0, unapply (exp (add (x^m/m! *t(k-m)(x), m=1..k)), x)) end: tt:= proc(k) option remember; unapply ((t(k)-t(k-1))(x), x) end: T:= proc(n, k) option remember; coeff (series (tt(k)(x), x, n+1), x, n) *n! end:
%p A218106 a:= n-> T(n+6,n): seq (a(n), n=0..20);
%t A218106 m = 6; f[0, _] = 1; f[k_, x_] := f[k, x] = Exp[Sum[x^m/m!*f[k-m, x], {m, 1, k}]]; (* t = A135302 *) t[0, 0] = 1; t[_, 0] = 0; t[n_, k_] := t[n, k] = SeriesCoefficient[f[k, x], {x, 0, n}]*n!; a[0] = 0; a[n_] := t[n+m, n]-t[n+m, n-1]; Table[a[n], {n, 0, 20}] (* _Jean-François Alcover_, Feb 14 2014 *)
%K A218106 nonn
%O A218106 0,3
%A A218106 _Alois P. Heinz_, Oct 20 2012