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 A364617 #15 Apr 07 2025 07:46:23 %S A364617 1,3,280,17300,1075397,68846551,4263997124,267855152858, %T A364617 16785795917908,1051116421516975,65871551452359237, %U A364617 4126577980480405170,258538236543240798654,16197912784372244064693,1014813990592495583029006,63579642939479330198729573,3983348112669764700919476270 %N A364617 Number of tilings of a 7 X n rectangle using dominoes and trominoes (of any shape). %H A364617 Alois P. Heinz, <a href="/A364617/b364617.txt">Table of n, a(n) for n = 0..557</a> %H A364617 Wikipedia, <a href="https://en.wikipedia.org/wiki/Domino_(mathematics)">Domino (mathematics)</a> %H A364617 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tromino">Tromino</a> %e A364617 a(1) = 3: %e A364617 ._. ._. ._. %e A364617 | | | | | | %e A364617 |_| |_| | | %e A364617 | | | | |_| %e A364617 |_| | | | | %e A364617 | | |_| |_| %e A364617 | | | | | | %e A364617 |_| |_| |_| . %Y A364617 Column k=7 of A364457. %K A364617 nonn %O A364617 0,2 %A A364617 _Alois P. Heinz_, Jul 29 2023 %E A364617 Terms n>=4 had to be corrected as was pointed out by _Martin Fuller_ and _David Radcliffe_ - _Alois P. Heinz_, Apr 05 2025