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 A381812 #27 Mar 16 2025 13:08:33 %S A381812 1,1,2,5,3,6,11,7,10,17,11,16,25,15,22,33,21,28,41,27,34 %N A381812 Number of moves required to reach a position with the maximum number of heads in the game of blet with 2*n coins. %C A381812 See A075273 or Rodriguez Villegas, Sadun, and Voloch (2002) for the definition of blet. %C A381812 Rodriguez Villegas, Sadun, and Voloch (2002) prove that the maximum number of heads achievable is A047206(n). %H A381812 Michael S. Branicky, <a href="/A381812/a381812.py.txt">Python program for OEIS A381812</a> %H A381812 Fernando Rodriguez Villegas, Lorenzo Sadun, and José Felipe Voloch, <a href="https://doi.org/10.1080/00029890.2002.11919904">Blet: a mathematical puzzle</a>, The American Mathematical Monthly 109 (2002), Issue 8, 729-740. %e A381812 For n = 5, a(5) = 5 moves are needed to go from HTHTHTHTHT to a sequence with the maximum number A047206(5) = 8 of heads: HTHTHTHTHT -> THHTHTHTHH -> THHTHTTHTH -> THHHTHTHTH -> THHHHTHHTH -> HHHHHTHHHT. %o A381812 (Python) # see linked program %Y A381812 Cf. A047206, A075273, A381813, A381814. %K A381812 nonn,more %O A381812 2,3 %A A381812 _Pontus von Brömssen_, Mar 08 2025 %E A381812 a(17)-a(18) from _Michael S. Branicky_, Mar 11 2025 %E A381812 a(19)-a(22) from _Bert Dobbelaere_, Mar 15 2025