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A194911 Triangular array (and fractal sequence): row n is the permutation of (1,2,...,n) obtained from the increasing ordering of fractional parts {r}, {2r}, ..., {nr}, where r=2^(1/3). 4

%I #9 Mar 30 2012 18:57:44

%S 1,1,2,1,2,3,4,1,2,3,4,1,5,2,3,4,1,5,2,6,3,4,1,5,2,6,3,7,4,8,1,5,2,6,

%T 3,7,4,8,1,5,9,2,6,3,7,4,8,1,5,9,2,6,10,3,7,4,8,1,5,9,2,6,10,3,7,11,4,

%U 8,12,1,5,9,2,6,10,3,7,11,4,8,12,1,5,9,13,2,6,10,3,7,11,4,8,12

%N Triangular array (and fractal sequence): row n is the permutation of (1,2,...,n) obtained from the increasing ordering of fractional parts {r}, {2r}, ..., {nr}, where r=2^(1/3).

%C See A194832 for a general discussion. The triangle is not equal to A194841.

%e First nine rows:

%e 1

%e 1 2

%e 1 2 3

%e 4 1 2 3

%e 4 1 5 2 3

%e 4 1 5 2 6 3

%e 4 1 5 2 6 3 7

%e 4 8 1 5 2 6 3 7

%e 4 8 1 5 9 2 6 3 7

%t r = 2^(1/3);

%t t[n_] := Table[FractionalPart[k*r], {k, 1, n}];

%t f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@

%t Sort[t[n], Less]], {n, 1, 20}]] (* A194911 *)

%t TableForm[Table[Flatten[(Position[t[n], #1] &) /@

%t Sort[t[n], Less]], {n, 1, 15}]]

%t row[n_] := Position[f, n];

%t u = TableForm[Table[row[n], {n, 1, 20}]]

%t g[n_, k_] := Part[row[n], k];

%t p = Flatten[Table[g[k, n - k + 1], {n, 1, 13},

%t {k, 1, n}]] (* A194912 *)

%t q[n_] := Position[p, n]; Flatten[Table[q[n],

%t {n, 1, 80}]] (* A194913 *)

%Y Cf. A194832, A194912, A194913.

%K nonn,tabl

%O 1,3

%A _Clark Kimberling_, Sep 05 2011

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Last modified April 25 04:42 EDT 2024. Contains 371964 sequences. (Running on oeis4.)