A191538 Dispersion of (4*n-floor(n*sqrt(3))), by antidiagonals.

1, 3, 2, 7, 5, 4, 16, 12, 10, 6, 37, 28, 23, 14, 8, 84, 64, 53, 32, 19, 9, 191, 146, 121, 73, 44, 21, 11, 434, 332, 275, 166, 100, 48, 25, 13, 985, 753, 624, 377, 227, 109, 57, 30, 15, 2234, 1708, 1416, 856, 515, 248, 130, 69, 35, 17, 5067, 3874, 3212, 1942

Offset: 1

Author

Clark Kimberling, Jun 06 2011

Keywords

• nonn
• tabl

Comments

Background discussion: Suppose that s is an increasing sequence of positive integers, that the complement t of s is infinite, and that t(1)=1. The dispersion of s is the array D whose n-th row is (t(n), s(t(n)), s(s(t(n))), s(s(s(t(n)))), ...). Every positive integer occurs exactly once in D, so that, as a sequence, D is a permutation of the positive integers. The sequence u given by u(n)=(number of the row of D that contains n) is a fractal sequence. Examples:

(1) s=A000040 (the primes), D=A114537, u=A114538.

(2) s=A022343 (without initial 0), D=A035513 (Wythoff array), u=A003603.

(3) s=A007067, D=A035506 (Stolarsky array), u=A133299.

More recent examples of dispersions: A191426-A191455 and A191536-A191545.

Examples

			Northwest corner:
  1,  3,  7,  16,  37, ...
  2,  5, 12,  28,  64, ...
  4, 10, 23,  53, 121, ...
  6, 14, 32,  73, 166, ...
  8, 19, 44, 100, 227, ...
		

Links

• G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened

Crossrefs

Cf. A114537, A035513, A035506.

Programs

Mathematica

(* Program generates the dispersion array T of the increasing sequence f[n] *)
r=40; r1=12; c=40; c1=12; f[n_] :=4n-Floor[n*Sqrt[3]]   (* complement of column 1 *)
mex[list_] := NestWhile[#1 + 1 &, 1, Union[list][[#1]] <= #1 &, 1, Length[Union[list]]]
rows = {NestList[f, 1, c]};
Do[rows = Append[rows, NestList[f, mex[Flatten[rows]], r]], {r}];
t[i_, j_] := rows[[i, j]];
TableForm[Table[t[i, j], {i, 1, r1}, {j, 1, c1}]]  (* A191538 array *)
Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191538 sequence *)