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 A258246 #4 Jun 11 2015 10:36:21 %S A258246 0,2,4,1,3,5,3,5,7,5,7,9,2,4,6,4,6,8,6,8,10,4,6,8,10,6,8,10,8,10,12,6, %T A258246 8,10,8,10,12,10,12,14,3,5,7,5,7,9,11,7,9,11,5,7,9,7,9,11,9,11,13,7,9, %U A258246 11,9,11,13,11,13,15,17,5,7,9,7,9,11,9,11,13 %N A258246 Number of steps from n to 0, where allowable steps are x -> [x/Pi] if x = is in A022844 (the Beatty sequence for Pi) and x -> [Pi*x] otherwise, where [ ] = floor. %C A258246 a(n) = number of edges from 0 to n in the tree at A258245. %H A258246 Clark Kimberling, <a href="/A258246/b258246.txt">Table of n, a(n) for n = 0..10000</a> %e A258246 8->25->7->21->6->1->3->0, so that a(8) = 7. %t A258246 r = Pi; w = Table[Floor[r*n], {n, 1, 1000}]; %t A258246 f[x_] := If[MemberQ[w, x], Floor[x/r], Floor[r*x]]; %t A258246 g[x_] := Drop[FixedPointList[f, x], -1]; %t A258246 Table[-1+ Length[g[n]], {n, 0, 100}] %Y A258246 Cf. A022844, A258245, A258212. %K A258246 nonn,easy %O A258246 0,2 %A A258246 _Clark Kimberling_, Jun 08 2015