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 A387261 #21 Aug 29 2025 16:12:07 %S A387261 2,4,6,2236,1026,275848876,649346842,61550866190068,2737872156886, %T A387261 5556238701119487884,33857036312840796476194, %U A387261 3393041394611453189295265268,218370486707916654640780231642,112630244896738642814653528498087299988,14364898791782224577113184680141626682 %N A387261 a(n) is the numerator of the winning probability of the starting player to reach n points first in the game "Risk or Safety", assuming optimal play. %C A387261 The total number of different strategies is given in A387260. See there for more information. %e A387261 a(2) = 4: For n=2, the optimal strategy is never to stop, but always try to get two consecutive heads. The winning probability is 1/4*(1 + (3/4)^2 + (3/4)^4 + ...) = 4/7. %Y A387261 A387262 are the corresponding denominators. %Y A387261 Cf. A002411, A349697, A349698, A387260. %K A387261 nonn,frac,hard,new %O A387261 1,1 %A A387261 _Ruediger Jehn_, Aug 24 2025 %E A387261 More terms from _Jinyuan Wang_, Aug 29 2025