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 A249762 #33 Feb 06 2017 17:52:02 %S A249762 1,1,3,5,13,50,133,360,875,2254,6336,17331,47199,124476,330344,889454, %T A249762 2400961,6485476,17392906,46616158,125153478,336529923,905611165, %U A249762 2434088873,6539233985,17567977887,47214493386,126927551197,341177175540,916960655233 %N A249762 Number of tilings of a 5 X n rectangle using n pentominoes of shapes F, I, L. %H A249762 Alois P. Heinz, <a href="/A249762/b249762.txt">Table of n, a(n) for n = 0..1000</a> %H A249762 Vaclav Kotesovec, <a href="/A249762/a249762.txt">G.f. and the recurrence (of order 315)</a> %H A249762 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pentomino">Pentomino</a> %F A249762 a(n) ~ c * d^n, where d = 2.6877447474867836174937272605197376719631593933016281800670782370745298422..., c = 0.3236150736074998563483897952085529328299218049725560430481595704054051228... (1/d is the root of the denominator, see g.f.). - _Vaclav Kotesovec_, May 19 2015 %e A249762 a(4) = 13: %e A249762 ._______. ._______. ._______. %e A249762 | | | | | | ._| ._| | | ._| | %e A249762 | | | | | | |_. | | | | | | | %e A249762 | | | | | | | |_| | | | | | | %e A249762 | | | | | |_| ._| | | |_| | | %e A249762 |_|_|_|_| (1) |___|___| (2) |_|___|_| (2) %e A249762 ._______. ._______. ._______. %e A249762 | ._| | | | ._| ._| | ._|_. | %e A249762 | | | | | | | | | | | | | | | %e A249762 | | | | | | | | | | | | | | | %e A249762 |_| | | | |_| |_| | |_| | |_| %e A249762 |___|_|_| (4) |___|___| (2) |___|___| (2) . %Y A249762 Cf. A174249, A233427, A247443, A247680, A251617, A251737, A257866, A264765. %K A249762 nonn %O A249762 0,3 %A A249762 _Alois P. Heinz_, Dec 03 2014