A114538 -id:A114538 - cp's OEIS frontend

A191451 Dispersion of (3*n-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

Clark Kimberling, Jun 05 2011

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.

			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

Cf. A114537, A035513, A035506, A191449.

(* 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 *)

A022447 Fractal sequence of the dispersion of the primes.

Original entry on oeis.org

1, 1, 1, 2, 1, 3, 2, 4, 5, 6, 1, 7, 3, 8, 9, 10, 2, 11, 4, 12, 13, 14, 5, 15, 16, 17, 18, 19, 6, 20, 1, 21, 22, 23, 24, 25, 7, 26, 27, 28, 3, 29, 8, 30, 31, 32, 9, 33, 34, 35, 36, 37, 10, 38, 39, 40, 41, 42, 2, 43, 11, 44, 45, 46, 47, 48, 4, 49, 50, 51, 12, 52, 13, 53, 54, 55, 56, 57, 14

Offset: 1

Clark Kimberling

nonn

			From _Sean A. Irvine_, May 20 2019: (Start)
The prime counting function, pi(n), is iterated (possibly zero times) until a nonprime is reached.  If the result of this iteration is m, then a(n) = m - pi(m).  Examples:
n=11: pi(11)=5, pi(5)=3, pi(3)=2, pi(2)=1. Hence, m=1 and so a(11) = 1-pi(1) = 1.
n=12: is already nonprime, hence m=12 and so a(12) = 12-pi(12) = 7.
n=13: pi(13)=6 (a nonprime), hence m=6 and so a(13) = 6-pi(6) = 3.
(End)

C. Kimberling, Fractal sequences and interspersions, Ars Combinatoria, vol. 45, p. 157, 1997.

G. C. Greubel, Table of n, a(n) for n = 1..10000
Sean A. Irvine, Java program (github)
C. Kimberling, Interspersions

Cf. A000720, A022446, A114537, A114538, A114577.

m = 30; list = Table[Length[NestWhileList[PrimePi, n, PrimeQ]], {n, m}]; Table[Length@Position[Take[list, k], list[[k]]], {k, Length[list]}] (* Birkas Gyorgy, Apr 04 2011 *)
primefractal[n_]:= (# - PrimePi[#]) &@NestWhile[PrimePi, n, PrimeQ]; Array[primefractal, 30] (* Birkas Gyorgy, Apr 04 2011 *)

Terms a(67) onward added by G. C. Greubel, Feb 28 2018

Offset corrected by Sean A. Irvine, May 20 2019

A114578 Transposition sequence of the dispersion of the composite numbers.

Original entry on oeis.org

1, 4, 9, 2, 16, 6, 26, 12, 3, 21, 39, 8, 56, 33, 15, 5, 78, 25, 106, 49, 10, 69, 141, 38, 18, 7, 94, 28, 184, 125, 236, 55, 14, 77, 164, 42, 296, 24, 11, 105, 356, 36, 416, 212, 140, 270, 476, 60, 20, 84, 183, 52, 536, 330, 32, 13, 115, 390, 596, 48, 656, 450, 235

Offset: 1

Clark Kimberling, Dec 09 2005

nonn

A self-inverse permutation of the positive integers.

			Start with the northwest corner of T:
1 4 9 16 26
2 6 12 21 33
3 8 15 25 38
5 10 18 28 42
a(1)=1 because 1=T(1,1) and T(1,1)=1.
a(2)=4 because 2=T(2,1) and T(1,2)=4.
a(3)=9 because 3=T(3,1) and T(1,3)=9.
a(10)=21 because 10=T(4,2) and T(2,4)=21.

Cf. A114577.

Suppose (as at A114538) that T is a rectangular array consisting of all the positive integers, each exactly once. The transposition sequence of T is obtained by placing T(i, j) in position T(j, i) for all i and j.

A114882 Transposition sequence of A114881.

Original entry on oeis.org

1, 3, 2, 5, 4, 7, 6, 8, 10, 9, 12, 11, 16, 24, 18, 13, 22, 15, 28, 48, 30, 17, 36, 14, 40, 120

Offset: 1

Clark Kimberling, Jan 03 2006

nonn

A self-inverse permutation of the natural numbers.

			Start with the northwest corner of A114881:
1 3 5 7 9
2 8 14 20 26
4 24 34 54 64
6 48 76 90 118
a(1)=1 because 1=T(1,1) and T(1,1)=1.
a(2)=3 because 2=T(2,1) and T(1,2)=3.
a(3)=2 because 3=T(1,2) and T(2,1)=2.
a(20)=48 because 20=T(2,4) and T(4,2)=48.

Cf. A083140, A114881.

(See A114538 for definition of transposition sequence.)

A191429 Dispersion of ([n*sqrt(2)+2]), where [ ]=floor, by antidiagonals.

Original entry on oeis.org

1, 3, 2, 6, 4, 5, 10, 7, 9, 8, 16, 11, 14, 13, 12, 24, 17, 21, 20, 18, 15, 35, 26, 31, 30, 27, 23, 19, 51, 38, 45, 44, 40, 34, 28, 22, 74, 55, 65, 64, 58, 50, 41, 33, 25, 106, 79, 93, 92, 84, 72, 59, 48, 37, 29, 151, 113, 133, 132, 120, 103, 85, 69, 54, 43, 32, 215, 161, 190, 188, 171, 147, 122, 99, 78, 62, 47, 36

Offset: 1

Clark Kimberling, Jun 03 2011

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.

			Northwest corner:
  1...3...6...10..16
  2...4...7...11..17
  5...9...14..21..31
  8...13..20..30..44
  12..18..27..40..58

Cf. A114537, A035513, A035506.

(* Program generates the dispersion array T of increasing sequence f[n] *)
r = 40; r1 = 12;  (* r=# rows of T to compute, r1=# rows to show *)
c = 40; c1 = 12;   (* c=# cols to compute, c1=# cols to show *)
x = Sqrt[2];
f[n_] := Floor[n*x + 2] (* f(n) is 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]];  (* the array T *)
TableForm[
Table[t[i, j], {i, 1, 10}, {j, 1, 10}]] (* A191429 array *)
Flatten[Table[
  t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191429 sequence *)
(* Program by Peter J. C. Moses, Jun 01 2011 *)

A191432 Dispersion of ([n*x+1/x]), where x=sqrt(2) and [ ]=floor, by antidiagonals.

Original entry on oeis.org

1, 2, 5, 3, 7, 8, 4, 10, 12, 11, 6, 14, 17, 16, 15, 9, 20, 24, 23, 21, 18, 13, 28, 34, 33, 30, 26, 22, 19, 40, 48, 47, 43, 37, 31, 25, 27, 57, 68, 67, 61, 53, 44, 36, 29, 38, 81, 96, 95, 86, 75, 62, 51, 41, 32, 54, 115, 136, 135, 122, 106, 88, 72, 58, 45, 35, 77, 163, 193, 191, 173, 150, 125, 102, 82, 64, 50, 39

Offset: 1

Clark Kimberling, Jun 03 2011

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.
Conjecture: It appears this sequence is related to the even numbers with odd abundance A088827. Looking at the table format if the columns represent the powers of 2 (starting at 2^1) and the rows represent the squares of odd numbers, then taking the product of a term's row and column gives the n-th term in A088827. Example: A088827(67) = (7^2) * (2^6) = 3136. - John Tyler Rascoe, Jul 12 2022

			Northwest corner:
   1    2    3    4    6    9
   5    7   10   14   20   28
   8   12   17   24   34   48
  11   16   23   33   47   67
  15   21   30   43   61   86

Michel Marcus, Antidiagonals n = 1..100, flattened

Cf. A114537, A035513, A035506, A088827.

Cf. A001953, A001954.

(* Program generates the dispersion array T of increasing sequence f[n] *)
r = 40; r1 = 12;  (* r=# rows of T, r1=# rows to show *)
c = 40; c1 = 12;  (* c=# cols of T, c1=# cols to show *)
x = Sqrt[2];
f[n_] := Floor[n*x + 1/x] (* f(n) is 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}]] (* A191432 array *)
Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191432 sequence *)
(* Program by Peter J. C. Moses, Jun 01 2011 *)

s(n) = my(x=quadgen(8)); floor(n*x+1/x);  \\ A001953
t(n) = floor((n+1/2)*(2+quadgen(8))); \\ A001954
T(n, k) = my(x = t(n-1)); for (i=2, k, x = s(x);); x; \\ Michel Marcus, Jul 13 2022

A191436 Dispersion of ([n*x+n+x-1]), where x=(golden ratio) and [ ]=floor, by antidiagonals.

Original entry on oeis.org

1, 4, 2, 12, 6, 3, 33, 17, 9, 5, 88, 46, 25, 14, 7, 232, 122, 67, 38, 19, 8, 609, 321, 177, 101, 51, 22, 10, 1596, 842, 465, 266, 135, 59, 27, 11, 4180, 2206, 1219, 698, 355, 156, 72, 30, 13, 10945, 5777, 3193, 1829, 931, 410, 190, 80, 35, 15, 28656, 15126

Offset: 1

Clark Kimberling, Jun 04 2011

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.

			Northwest corner:
  1....4....12...33...88
  2....6....17...46...122
  3....9....25...67...177
  5....14...38...101..266
  7....19...51...135..355

Cf. A114537, A035513, A035506.

(* Program generates the dispersion array T of increasing sequence f[n] *)
r = 40; r1 = 12;  c = 40; c1 = 12;  x = GoldenRatio;
f[n_] := Floor[n*x+n+x-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}]]
(* A191436 array *)
Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191436 sequence *)
(* Program by Peter J. C. Moses, Jun 01 2011 *)

A191439 Dispersion of ([n*sqrt(2)+n+1/2]), where [ ]=floor, by antidiagonals.

Original entry on oeis.org

1, 2, 3, 5, 7, 4, 12, 17, 10, 6, 29, 41, 24, 14, 8, 70, 99, 58, 34, 19, 9, 169, 239, 140, 82, 46, 22, 11, 408, 577, 338, 198, 111, 53, 27, 13, 985, 1393, 816, 478, 268, 128, 65, 31, 15, 2378, 3363, 1970, 1154, 647, 309, 157, 75, 36, 16, 5741, 8119, 4756

Offset: 1

Clark Kimberling, Jun 04 2011

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.

			Northwest corner:
  1....2....5....12...29
  3....7....17...41...99
  4....10...24...58...140
  6....14...34...82...198
  8....19...46...111..268

Robbert Fokkink, The Pell Tower and Ostronometry, arXiv:2309.01644 [math.CO], 2023.

Cf. A114537, A035513, A035506, A191438.

(* Program generates the dispersion array T of increasing sequence f[n] *)
r=40; r1=12; c=40; c1=12;  x = Sqr[2];
f[n_] := Floor[n*x+n+1/2] (* 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}]]
(* A191439 array *)
Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191439 sequence *)
(* Program by Peter J. C. Moses, Jun 01 2011 *)

A191446 Dispersion of [n*sqrt(5)], where [ ]=floor, by antidiagonals.

Original entry on oeis.org

1, 2, 3, 4, 6, 5, 8, 13, 11, 7, 17, 29, 24, 15, 9, 38, 64, 53, 33, 20, 10, 84, 143, 118, 73, 44, 22, 12, 187, 319, 263, 163, 98, 49, 26, 14, 418, 713, 588, 364, 219, 109, 58, 31, 16, 934, 1594, 1314, 813, 489, 243, 129, 69, 35, 18, 2088, 3564, 2938, 1817

Offset: 1

Clark Kimberling, Jun 05 2011

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.

			Northwest corner:
  1...2....4....8...17
  3...6....13...29..64
  5...11...24...53..118
  7...15...33...73..163
  9...20...44...98..219

Cf. A114537, A035513, A035506.

(* Program generates the dispersion array T of increasing sequence f[n] *)
r=40; r1=12; c=40; c1=12;  x = Sqrt[5];
f[n_] := Floor[n*x] (* 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}]]
(* A191446 array *)
Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191446 sequence *)
(* Program by Peter J. C. Moses, Jun 01 2011 *)

Corrected typo in name and fixed Mathematica program by Vaclav Kotesovec, Oct 24 2014

A191540 Dispersion of (floor(2nsqrt(2))), by antidiagonals.

Original entry on oeis.org

1, 2, 3, 5, 8, 4, 14, 22, 11, 6, 39, 62, 31, 16, 7, 110, 175, 87, 45, 19, 9, 311, 494, 246, 127, 53, 25, 10, 879, 1397, 695, 359, 149, 70, 28, 12, 2486, 3951, 1965, 1015, 421, 197, 79, 33, 13, 7031, 11175, 5557, 2870, 1190, 557, 223, 93, 36, 15, 19886, 31607

Offset: 1

Clark Kimberling, Jun 06 2011

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.

			Northwest corner:
  1,  2,  5,  14,  39, ...
  3,  8, 22,  62, 175, ...
  4, 11, 31,  87, 246, ...
  6, 16, 45, 127, 359, ...
  7, 19, 53, 149, 421, ...

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

Cf. A114537, A035513, A035506.

(* Program generates the dispersion array T of the increasing sequence f[n] *)
r=40; r1=12; c=40; c1=12; f[n_] :=Floor[2n*Sqrt[2]]   (* 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}]]  (* A191540 array *)
Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191540 sequence *)

cp's OEIS Frontend

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

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A022447 Fractal sequence of the dispersion of the primes.

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Extensions

A114578 Transposition sequence of the dispersion of the composite numbers.

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A114882 Transposition sequence of A114881.

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A191429 Dispersion of ([n*sqrt(2)+2]), where [ ]=floor, by antidiagonals.

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A191432 Dispersion of ([n*x+1/x]), where x=sqrt(2) and [ ]=floor, by antidiagonals.

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A191436 Dispersion of ([n*x+n+x-1]), where x=(golden ratio) and [ ]=floor, by antidiagonals.

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Mathematica

A191439 Dispersion of ([n*sqrt(2)+n+1/2]), where [ ]=floor, by antidiagonals.

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Mathematica

A191446 Dispersion of [n*sqrt(5)], where [ ]=floor, by antidiagonals.

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A191540 Dispersion of (floor(2nsqrt(2))), by antidiagonals.