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 A014225 #25 Jul 08 2025 02:55:36 %S A014225 1,2,4,8,20 %N A014225 Number of initial pieces needed to reach level n in the Solitaire Army game. %C A014225 Level 4 is the highest level that can be reached. %D A014225 E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Academic Press, NY, 2 vols., 1982, see p. 715. %H A014225 Burkard Polster, <a href="https://www.youtube.com/watch?v=BMPa0FA65Fk">How did Fibonacci beat the Solitaire army?</a>, Mathologer video, 2022. %H A014225 Zvezdelina Stankova and Brady Haran, <a href="https://www.youtube.com/watch?v=Or0uWM9bT5w">Conway Checkers (proof)</a>, Numberphile video, 2018. %H A014225 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConwaysSoldiers.html">Conway's Soldiers</a> %Y A014225 Cf. A000980. %K A014225 nonn,fini,full %O A014225 0,2 %A A014225 _N. J. A. Sloane_