cp's OEIS Frontend

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.

A245221 Decimal expansion of sup{f(n,1)}, where f(1,x) = x + 1 and thereafter f(n,x) = x + 1 if n is in A022838, else f(n,x) = 1/x.

Original entry on oeis.org

2, 7, 2, 0, 7, 6, 6, 4, 5, 0, 7, 2, 9, 4, 7, 5, 2, 9, 7, 5, 4, 6, 9, 5, 1, 7, 3, 4, 8, 1, 7, 1, 5, 1, 3, 2, 4, 2, 5, 4, 7, 4, 9, 7, 9, 6, 1, 7, 1, 4, 6, 4, 1, 6, 7, 9, 0, 0, 0, 8, 2, 8, 3, 6, 6, 8, 7, 6, 6, 2, 4, 2, 1, 2, 1, 6, 7, 7, 7, 9, 0, 9, 7, 7, 8, 6
Offset: 1

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Author

Clark Kimberling, Jul 14 2014

Keywords

Comments

See Comments at A245215.

Examples

			c = 0.367543491184951248721260972541092540...  The first 12 numbers f(n,1) comprise S(12) = {1, 2, 1/2, 3/2, 2/3, 5/3, 8/3, 3/8, 11/8, 8/11, 19/11, 11/19}; min(S(12)) = 3/8 = 0.375... and max(S(12)) = 8/3 = 2.666...
		

Crossrefs

Cf. A226080 (infinite Fibonacci tree), A245215, A245217, A245220, A245222.

Programs

  • Mathematica
    tmpRec = $RecursionLimit; $RecursionLimit = Infinity; u[x_] := u[x] = x + 1; d[x_] := d[x] = 1/x; r = Sqrt[3]; w = Table[Floor[k*r], {k, 2000}]; s[1] = 1; s[n_] := s[n] = If[MemberQ[w, n - 1], u[s[n - 1]], d[s[n - 1]]]; $RecursionLimit = tmpRec;
    m = Max[N[Table[s[n], {n, 1, 4000}], 300]]
    t = RealDigits[m]  (* A245221 *)
    (* Peter J. C. Moses, Jul 04 2014 *)

Formula

a(n)*inf{f(n,1)} = 1.