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 A285361 #63 Sep 08 2022 08:46:19
%S A285361 0,1,11,64,282,1071,3729,12310,39296,122773,378279,1154988,3505542,
%T A285361 10598107,31957661,96200098,289255020,869075073,2609845875,7834779640,
%U A285361 23514823730,70565441671,211738266921,635298685614,1906063827672,5718527025901,17156252164799,51470098670020
%N A285361 The number of tight 3 X n pavings.
%C A285361 Also, zero together with the third row of the square array A285357.
%H A285361 Robert Israel, <a href="/A285361/b285361.txt">Table of n, a(n) for n = 0..2092</a>
%H A285361 D. E. Knuth (Proposer), <a href="http://dx.doi.org/10.4169/amer.math.monthly.124.8.754">Problem 12005</a>, Amer. Math. Monthly 124 (No. 8, Oct. 2017), page 755. For solution see op. cit., 126 (No. 7, 2019), 660-664.
%H A285361 Roberto Tauraso, <a href="http://www.mat.uniroma2.it/~tauraso/AMM/AMM12005.pdf">Problem 12005, Proposed solution</a>.
%H A285361 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (8,-24,34,-23,6).
%F A285361 a(n) = (1/4) * (3^(n+3) - 5*2^(n+4) + 4*n^2 + 26*n + 53). - _Hugo Pfoertner_, Mar 14 2018
%F A285361 G.f.: (x+3*x^2)/((1-x)^3*(1-2*x)*(1-3*x)). - _Robert Israel_, Mar 15 2018
%e A285361 For n=2 the 11 solutions are 12|32|44, 12|13|44, 12|33|44, 11|22|34, 11|23|43, 12|13|43, 12|32|42, 12|13|14, 12|32|34, 11|23|24, 11|23|44.
%e A285361 (Use the "interactive illustration" link in A285357 (with n=3!) for a graphic display.)
%p A285361 seq((1/4) * (3^(n+3) - 5*2^(n+4) + 4*n^2 + 26*n + 53),n=0..50); # _Robert Israel_, Mar 15 2018
%t A285361 LinearRecurrence[{8, -24, 34, -23, 6}, {0, 1, 11, 64, 282}, 30] (* _Vincenzo Librandi_, Mar 16 2018 *)
%o A285361 (Magma) [(1/4)*(3^(n+3)-5*2^(n+4)+4*n^2+26*n+53): n in [0..30]]; // _Vincenzo Librandi_, Mar 16 2018
%Y A285361 Cf. A285357, A298362, A336732, A336734.
%K A285361 nonn,easy
%O A285361 0,3
%A A285361 _Don Knuth_, Apr 17 2017
%E A285361 a(10) from _Hugo Pfoertner_, Jan 17 2018
%E A285361 More terms from _M. F. Hasler_, Jan 21 2018