A191451 Dispersion of (3n-2), for n>=2, by antidiagonals.

1, 4, 2, 13, 7, 3, 40, 22, 10, 5, 121, 67, 31, 16, 6, 364, 202, 94, 49, 19, 8, 1093, 607, 283, 148, 58, 25, 9, 3280, 1822, 850, 445, 175, 76, 28, 11, 9841, 5467, 2551, 1336, 526, 229, 85, 34, 12, 29524, 16402, 7654, 4009, 1579, 688, 256, 103, 37, 14, 88573

Offset

1,2

Comments

Row 1: A003462

Row 2: A060816

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.

Links

Table of n, a(n) for n=1..56.

Example

Northwest corner:
1...4....13...40...121
2...7....22...67...202
3...10...31...94...283
5...16...49...148..445
6...19...58...175..526

Mathematica

(* Program generates the dispersion array T of increasing sequence f[n] *)
r=40; r1=12; c=40; c1=12;
f[n_] :=3n+1 (* 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, 10}, {j, 1, 10}]]
(* A191451 array *)
Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191451 sequence *)
(* Program by Peter J. C. Moses, Jun 01 2011 *)

Crossrefs

Cf. A114537, A035513, A035506, A191449.

Sequence in context: A069836 A224820 A125153 * A193950 A180194 A193853

Adjacent sequences: A191448 A191449 A191450 * A191452 A191453 A191454

Keyword

nonn,tabl

Author

Clark Kimberling, Jun 05 2011

Status

approved