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 A237357 #19 Mar 20 2024 13:52:14 %S A237357 1,6,64,616,5936,57408,554624,5359040,51781696,500337216,4834483264, %T A237357 46712942656,451361370176,4361255727168,42140406169664, %U A237357 407179478511680,3934350491492416,38015456589811776,367322368167936064,3549233239845138496,34294281215843786816 %N A237357 The number of tilings of the 3 X 3 X (2n) room with 1 X 2 X 3 boxes. %C A237357 The count compiles all arrangements without respect to symmetry: Stacks that are equivalent after rotations or flips through any of the 3 axes or 3 planes are counted with multiplicity. %H A237357 Vincenzo Librandi, <a href="/A237357/b237357.txt">Table of n, a(n) for n = 0..200</a> %H A237357 R. J. Mathar, <a href="http://arxiv.org/abs/1406.7788">Tilings of rectangular regions by rectangular tiles: counts derived from transfer matrices</a>, arXiv:1406.7788 [math.CO], eq. (57). %H A237357 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (7,22,36). %F A237357 G.f.: (1-x)/(-22*x^2-7*x-36*x^3+1). %p A237357 A237357 := proc(n) %p A237357 (1-x)/ (-22*x^2-7*x-36*x^3+1) ; %p A237357 coeftayl(%,x=0,n) ; %p A237357 end proc: %p A237357 seq(A237357(n),n=0..20) ; %t A237357 CoefficientList[Series[(1 - x)/(-22 x^2 - 7 x - 36 x^3 + 1), {x, 0, 30}], x] (* _Vincenzo Librandi_, Feb 08 2014 *) %t A237357 LinearRecurrence[{7,22,36},{1,6,64},30] (* _Harvey P. Dale_, Mar 20 2024 *) %Y A237357 Cf. A000079 (2 X 2 X n rooms), A103143 (2 X 3 X n rooms). %K A237357 nonn,easy %O A237357 0,2 %A A237357 _R. J. Mathar_, Feb 07 2014