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 A047707 #45 Mar 07 2020 01:28:54
%S A047707 0,0,0,2,64,1090,14000,153762,1533504,14356610,128722000,1119607522,
%T A047707 9528462944,79817940930,660876543600,5424917141282,44246078560384,
%U A047707 359144709794050,2904688464582800,23429048035827042,188593339362097824
%N A047707 Number of monotone Boolean functions of n variables with 3 mincuts. Also Sperner systems with 3 blocks.
%C A047707 The paper by G. Kilibarda, Enumeration of certain classes of antichains, Publications de l'Institut Mathematique, Nouvelle série, 97 (111) (2015), mentions many sequences, but since only very condensed formulas are given, it is hard to match them with entries in the OEIS. It would be nice to add this reference to all the sequences that it mentions. - _N. J. A. Sloane_, Jan 01 2016
%C A047707 Term a(1108) has 1000 decimal digits. - _Michael De Vlieger_, Jan 26 2016
%D A047707 L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 292, #8, s(n,3).
%H A047707 Michael De Vlieger, <a href="/A047707/b047707.txt">Table of n, a(n) for n = 0..1107</a>
%H A047707 K. S. Brown, <a href="http://www.mathpages.com/home/kmath030.htm">Dedekind's problem.</a>
%H A047707 Vladeta Jovovic, <a href="/A047707/a047707.pdf">Illustration for A016269, A047707, A051112-A051118</a>
%H A047707 G. Kilibarda, <a href="http://dx.doi.org/10.2298/PIM140406001K">Enumeration of certain classes of antichains</a>, Publications de l'Institut Mathematique, Nouvelle série, 97 (111) (2015), 69-87 DOI: 10.2298/PIM140406001K. See page 86, formula for alpha^hat(3,n).
%H A047707 Goran Kilibarda and Vladeta Jovovic, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL7/Kilibarda/kili2.html">Antichains of Multisets</a>, J. Integer Seqs., Vol. 7, 2004.
%H A047707 <a href="/index/Bo#Boolean">Index entries for sequences related to Boolean functions</a>
%H A047707 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (28,-315,1820,-5684,9072,-5760).
%F A047707 a(n) = (2^n)*(2^n - 1)*(2^n - 2)/6 - (6^n - 5^n - 4^n + 3^n).
%F A047707 G.f.: -2*x^3*(36*x^2-4*x-1)/((2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)*(8*x-1)). - _Colin Barker_, Jul 31 2012
%F A047707 a(n) = Binomial(2^n,3) - (6^n - 5^n - 4^n + 3^n). - _Ross La Haye_, Jan 26 2016
%t A047707 Table[Binomial[2^n, 3] - (6^n - 5^n - 4^n + 3^n), {n, 20}] (* or *)
%t A047707 CoefficientList[Series[-2 x^3 (36 x^2 - 4 x - 1)/((2 x - 1) (3 x - 1) (4 x - 1) (5 x - 1) (6 x - 1) (8 x - 1)), {x, 0, 20}], x] (* _Michael De Vlieger_, Jan 26 2016 *)
%o A047707 (PARI) a(n)=binomial(2^n,3)-(6^n-5^n-4^n+3^n) \\ _Charles R Greathouse IV_, Apr 08 2016
%Y A047707 Cf. A016269, A051112.
%K A047707 nonn,easy
%O A047707 0,4
%A A047707 _N. J. A. Sloane_