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).

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, 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, 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

Offset

1,2

Comments

See A194832 for a general discussion.

Links

Table of n, a(n) for n=1..94.

Example

First nine rows:
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 8 4
7 3 6 2 9 5 1 8 4

Mathematica

r = Sqrt[3];
t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]]  (* A194838 *)
TableForm[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 15}]]
row[n_] := Position[f, n];
u = TableForm[Table[row[n], {n, 1, 20}]]
g[n_, k_] := Part[row[n], k];
p = Flatten[Table[g[k, n - k + 1], {n, 1, 13},
{k, 1, n}]]  (* A194839 *)
q[n_] := Position[p, n]; Flatten[
Table[q[n], {n, 1, 80}]]  (* A194840 *)

Crossrefs

Cf. A194832, A194839, A194840.

Sequence in context: A131756 A212620 A194859 * A085014 A082074 A132283

Adjacent sequences: A194835 A194836 A194837 * A194839 A194840 A194841

Keyword

nonn,tabl

Author

Clark Kimberling, Sep 03 2011

Status

approved