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 A354011 #8 May 16 2022 14:56:36 %S A354011 1,0,7,8,81,184,1051,3176,14609,50408,210903,773888,3102369,11711856, %T A354011 46045259,176114128,686258465,2640610128,10247733223,39540368248, %U A354011 153162778865,591718044968,2290106238779,8852558325048,34248315785777,132424316290104,512224146701367 %N A354011 Number of tilings of a 3 X n rectangle using 2 X 2 tiles, right trominoes and dominoes. %C A354011 For tiling algorithm, see A351322. %H A354011 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (2,9,-8,3,6,-3). %F A354011 G.f.: (1 - 2*x - 2*x^2 + 2*x^3 - x^4) / (1 - 2*x - 9*x^2 + 8*x^3 - 3*x^4 - 6*x^5 + 3*x^6). %F A354011 a(n)=2*a(n-1) + 9*a(n-2) - 8*a(n-3) + 3*a(n-4) + 6*a(n-5) - 3*a(n-6). %e A354011 a(2)=7: %e A354011 ___ ___ ___ ___ ___ ___ ___ %e A354011 | | |___| |_ | | _| |___| |___| |_|_| %e A354011 |___| | | | |_| |_| | |___| |_|_| |_|_| %e A354011 |___| |___| |___| |___| |___| |_|_| |___| %o A354011 (Maxima) See A352589. %Y A354011 Cf. A351322, A352589, A354010, A354012. %K A354011 nonn,easy %O A354011 0,3 %A A354011 _Gerhard Kirchner_, May 14 2022