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A194905 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=Pi. 6

%I #9 Apr 11 2015 10:08:06

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

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

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

%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=Pi.

%C See A194832 for a general discussion.

%e First nine rows:

%e 1

%e 1 2

%e 1 2 3

%e 1 2 3 4

%e 1 2 3 4 5

%e 1 2 3 4 5 6

%e 1 2 3 4 5 6 7

%e 8 1 2 3 4 5 6 7

%e 8 1 9 2 3 4 5 6 7

%t r = Pi;

%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}]] (* A194905 *)

%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}]] (* A194906 *)

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

%t {n, 1, 80}]] (* A194907 *)

%Y Cf. A194832, A194906, A194907.

%K nonn,tabl

%O 1,3

%A _Clark Kimberling_, Sep 05 2011

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Last modified April 16 05:35 EDT 2024. Contains 371697 sequences. (Running on oeis4.)