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 A364556 #21 Apr 05 2025 09:10:02 %S A364556 1,2,43,733,12688,226922,3927233,68846551,1204757533,21062468900, %T A364556 368521437132,6445706387345,112749099291387,1972235696214897, %U A364556 34498222540798726,603446574091501719,10555520988321750183,184637793249606497610,3229696298942838688793,56494043669663414794810 %N A364556 Number of tilings of a 5 X n rectangle using dominoes and trominoes (of any shape). %H A364556 Alois P. Heinz, <a href="/A364556/b364556.txt">Table of n, a(n) for n = 0..805</a> %H A364556 Wikipedia, <a href="https://en.wikipedia.org/wiki/Domino_(mathematics)">Domino (mathematics)</a> %H A364556 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tromino">Tromino</a> %e A364556 a(1) = 2: %e A364556 ._. ._. %e A364556 | | | | %e A364556 | | |_| %e A364556 |_| | | %e A364556 | | | | %e A364556 |_| |_| . %Y A364556 Column k=5 of A364457. %K A364556 nonn %O A364556 0,2 %A A364556 _Alois P. Heinz_, Jul 28 2023 %E A364556 Terms n>=4 had to be corrected as was pointed out by _Martin Fuller_ and _David Radcliffe_ - _Alois P. Heinz_, Apr 05 2025