login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A194838 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=sqrt(3). 4

%I #8 Mar 30 2012 18:57:44

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

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

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

%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=sqrt(3).

%C See A194832 for a general discussion.

%e First nine rows:

%e 1

%e 2 1

%e 3 2 1

%e 3 2 1 4

%e 3 2 5 1 4

%e 3 6 2 5 1 4

%e 7 3 6 2 5 1 4

%e 7 3 6 2 5 1 8 4

%e 7 3 6 2 9 5 1 8 4

%t r = Sqrt[3];

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

%t f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]] (* A194838 *)

%t TableForm[Table[Flatten[(Position[t[n], #1] &) /@ 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}]] (* A194839 *)

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

%t Table[q[n], {n, 1, 80}]] (* A194840 *)

%Y Cf. A194832, A194839, A194840.

%K nonn,tabl

%O 1,2

%A _Clark Kimberling_, Sep 03 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

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