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A194862 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=(1+sqrt(3))/2. 4

%I #7 Jul 30 2023 03:44:02

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

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

%U 11,3,6,9,1,12,4,7,10,2,5,8,11,3,6,9,1,12,4,7,10,2,13,5,8,11,3,14

%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=(1+sqrt(3))/2.

%C See A194832 for a general discussion.

%e First nine rows:

%e 1

%e 1 2

%e 3 1 2

%e 3 1 4 2

%e 3 1 4 2 5

%e 3 6 1 4 2 5

%e 3 6 1 4 7 2 5

%e 3 6 1 4 7 2 5 8

%e 3 6 9 1 4 7 2 5 8

%t r = (1 + Sqrt[3])/2;

%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}]] (* A194862 *)

%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}]] (* A194863 *)

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

%t {n, 1, 80}]] (* A194867 *)

%Y Cf. A194832, A194863, A194867.

%K nonn,tabl

%O 1,3

%A _Clark Kimberling_, Sep 04 2011

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Last modified April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)