A194844 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(5).

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

Offset

1,3

Comments

See A194832 for a general discussion.

Links

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

Example

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

Mathematica

r = Sqrt[5];
t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]]  (* A194844 *)
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}]]    (* A194845 *)
q[n_] := Position[p, n]; Flatten[
 Table[q[n], {n, 1, 80}]]   (* A194846 *)

Crossrefs

Cf. A194832, A194845, A194846.

Sequence in context: A120853 A175022 A243613 * A138528 A364604 A037125

Adjacent sequences: A194841 A194842 A194843 * A194845 A194846 A194847

Keyword

nonn,tabl

Author

Clark Kimberling, Sep 04 2011

Status

approved