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.

A054065 Fractal sequence induced by tau: for k >= 1, let p(k) be the permutation of 1,2,...,k obtained by ordering the fractional parts {h*tau} for h=1,2,...,k; then juxtapose p(1),p(2),p(3),...

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%I A054065 #26 Apr 15 2014 14:15:51
%S A054065 1,2,1,2,1,3,2,4,1,3,5,2,4,1,3,5,2,4,1,6,3,5,2,7,4,1,6,3,5,2,7,4,1,6,
%T A054065 3,8,5,2,7,4,9,1,6,3,8,5,10,2,7,4,9,1,6,3,8,5,10,2,7,4,9,1,6,11,3,8,5,
%U A054065 10,2,7,12,4,9,1,6,11,3,8,13,5,10,2,7,12,4,9,1,6,11,3,8,13,5,10,2,7,12,4,9
%N A054065 Fractal sequence induced by tau: for k >= 1, let p(k) be the permutation of 1,2,...,k obtained by ordering the fractional parts {h*tau} for h=1,2,...,k; then juxtapose p(1),p(2),p(3),...
%e A054065 p(1)=(1); p(2)=(2,1); p(3)=(2,1,3); p(4)=(2,4,1,3).
%e A054065 As a triangular array (see A194832), first nine rows:
%e A054065 1
%e A054065 2 1
%e A054065 2 1 3
%e A054065 2 4 1 3
%e A054065 5 2 4 1 3
%e A054065 5 2 4 1 6 3
%e A054065 5 2 7 4 1 6 3
%e A054065 5 2 7 4 1 6 3 8
%e A054065 5 2 7 4 9 1 6 3 8
%t A054065 r = (1 + Sqrt[5])/2;
%t A054065 t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
%t A054065 f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]] (* A054065 *)
%t A054065 TableForm[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 15}]]
%t A054065 row[n_] := Position[f, n];
%t A054065 u = TableForm[Table[row[n], {n, 1, 20}]]
%t A054065 g[n_, k_] := Part[row[n], k];
%t A054065 p = Flatten[Table[g[k, n - k + 1], {n, 1, 13}, {k, 1, n}]] (* A054069 *)
%t A054065 q[n_] := Position[p, n]; Flatten[Table[q[n], {n, 1, 80}]]  (* A054068 *)
%t A054065 (* _Clark Kimberling_, Sep 03 2011 *)
%t A054065 Flatten[Table[Ordering[Table[FractionalPart[GoldenRatio k], {k, n}]], {n, 10}]] (* _Birkas Gyorgy_, Jun 30 2012 *)
%Y A054065 Position of 1 in p(k) is given by A019446. Position of k in p(k) is given by A019587.  For related arrays and sequences, see A194832.
%K A054065 nonn
%O A054065 1,2
%A A054065 _Clark Kimberling_
%E A054065 Extended by _Ray Chandler_, Apr 18 2009