cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 49 results. Next

A194833 Rectangular array, by antidiagonals: row n gives the positions of n in the fractal sequence A194832; an interspersion.

Original entry on oeis.org

1, 2, 3, 5, 6, 4, 8, 10, 7, 9, 12, 14, 11, 13, 15, 18, 20, 16, 19, 21, 17, 24, 27, 22, 25, 28, 23, 26, 32, 35, 30, 33, 36, 31, 34, 29, 40, 44, 38, 42, 45, 39, 43, 37, 41, 49, 53, 47, 51, 55, 48, 52, 46, 50, 54, 60, 64, 57, 62, 66, 59, 63, 56, 61, 65, 58, 71, 76, 68
Offset: 1

Views

Author

Clark Kimberling, Sep 03 2011

Keywords

Comments

As a sequence, A194833 is a permutation of the positive integers; its inverse is A194834.

Examples

			Northwest corner:
1...2...5...8...12..18..24
3...6...10..14..20..27..35
4...7...11..16..22..30..38
9...13..19..25..33..42..51
15..21..28..36..45..55..66
		

Crossrefs

Programs

  • Mathematica
    r = -GoldenRatio;
    t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
    f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]]
    (* A194832 *)
    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}]] (* A194833 *)
    q[n_] := Position[p, n]; Flatten[Table[q[n], {n, 1, 80}]] (* A194834 *)

A374411 Triangle T(n, k) read by rows: Maximum number of linear patterns of length k in a circular permutation of length n taken from row n in A194832.

Original entry on oeis.org

1, 1, 2, 1, 2, 3, 1, 2, 6, 4, 1, 2, 6, 16, 5, 1, 2, 6, 20, 25, 6, 1, 2, 6, 24, 60, 36, 7, 1, 2, 6, 24, 85, 126, 49, 8, 1, 2, 6, 24, 100, 222, 196, 64, 9, 1, 2, 6, 24, 115, 390, 511, 288, 81, 10, 1, 2, 6, 24, 120, 558, 1085, 912, 405, 100, 11, 1, 2, 6, 24, 120, 654, 1911, 2328, 1458, 550, 121, 12
Offset: 1

Views

Author

Thomas Scheuerle, Jul 08 2024

Keywords

Comments

Pattern counting considers only one revolution otherwise every sufficiently long circular permutation, with enough revolutions allowed, contains every pattern.
Each column k is divisible by k, because as we count linear patterns inside a circular permutation, we may obtain all circular shifts of the subset which represents a particular pattern.

Examples

			The triangle begins:
   n| k: 1| 2| 3|  4|   5|   6|   7|  8|  9
  =========================================
  [1]    1
  [2]    1, 2
  [3]    1, 2, 3
  [4]    1, 2, 6,  4
  [5]    1, 2, 6, 16,   5
  [6]    1, 2, 6, 20,  25,   6
  [7]    1, 2, 6, 24,  60,  36,   7
  [8]    1, 2, 6, 24,  85, 126,  49,  8
  [9]    1, 2, 6, 24, 100, 222, 196, 64, 9
.
Row 5 of A194832 is [3, 1, 4, 2, 5].
T(5, 4) = 16 because we will find these 16 distinct patterns of length 4:
   [3, 1, 4, 2] [1, 4, 2, 3] [4, 2, 3, 1] [2, 3, 1, 4]
 These are rotations of the ordering [1, 4, 2, 3].
   [1, 4, 2, 5] [4, 2, 5, 1] [2, 5, 1, 4] [5, 1, 4, 2]
 These are rotations of the ordering [1, 3, 2, 4].
   [2, 5, 3, 1] [5, 3, 1, 2] [3, 1, 2, 5] [1, 2, 5, 3]
 These are rotations of the ordering [1, 2, 4, 3].
   [5, 3, 1, 4] [3, 1, 4, 5] [1, 4, 5, 3] [4, 5, 3, 1]
 These are rotations of the ordering [1, 3, 4, 2].
		

Crossrefs

Formula

T(n, k+1)/(k+1) <= A371823(n-1, k) <= A373778(n-1, k).

A054065 Fractal sequence induced by tau: for k >= 1, let p(k) be the permutation of 1,2,...,k obtained by ordering the fractional parts {h*tau} for h=1,2,...,k; then juxtapose p(1),p(2),p(3),...

Original entry on oeis.org

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

Views

Author

Keywords

Examples

			p(1)=(1); p(2)=(2,1); p(3)=(2,1,3); p(4)=(2,4,1,3).
As a triangular array (see A194832), first nine rows:
1
2 1
2 1 3
2 4 1 3
5 2 4 1 3
5 2 4 1 6 3
5 2 7 4 1 6 3
5 2 7 4 1 6 3 8
5 2 7 4 9 1 6 3 8
		

Crossrefs

Position of 1 in p(k) is given by A019446. Position of k in p(k) is given by A019587. For related arrays and sequences, see A194832.

Programs

  • Mathematica
    r = (1 + Sqrt[5])/2;
    t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
    f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]] (* A054065 *)
    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}]] (* A054069 *)
    q[n_] := Position[p, n]; Flatten[Table[q[n], {n, 1, 80}]]  (* A054068 *)
    (* Clark Kimberling, Sep 03 2011 *)
    Flatten[Table[Ordering[Table[FractionalPart[GoldenRatio k], {k, n}]], {n, 10}]] (* Birkas Gyorgy, Jun 30 2012 *)

Extensions

Extended by Ray Chandler, Apr 18 2009

A054073 Fractal sequence induced by sqrt(2): for k >= 1 let p(k) be the permutation of 1,2,...,k obtained by ordering the fractional parts {h*sqrt(2)} for h=1,2,...,k; then juxtapose p(1),p(2),p(3),...

Original entry on oeis.org

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

Views

Author

Keywords

Comments

A054073 generates the interspersion A054077; see A194832 and the Mathematica program.

Examples

			p(1)=(1); p(2)=(1,2); p(3)=(3,1,2); p(4)=(3,1,4,2).
When formatted as a triangle, the first 9 rows:
1
1 2
3 1 2
3 1 4 2
5 3 1 4 2
5 3 1 6 4 2
5 3 1 6 4 2 7
5 3 8 1 6 4 2 7
5 3 8 1 6 4 9 2 7
		

Crossrefs

Programs

  • Mathematica
    r = Sqrt[2];
    t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
    f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]],
    {n, 1, 20}]] (* A054073 *)
    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}]] (* A054077 *)
    q[n_] := Position[p, n]; Flatten[
    Table[q[n], {n, 1, 80}]]  (* A054076 *)
    (* Clark Kimberling, Sep 03 2011 *)

A194905 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=Pi.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Sep 05 2011

Keywords

Comments

See A194832 for a general discussion.

Examples

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

Crossrefs

Programs

  • Mathematica
    r = Pi;
    t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
    f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@
    Sort[t[n], Less]], {n, 1, 20}]]  (* A194905 *)
    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}]]  (* A194906 *)
    q[n_] := Position[p, n]; Flatten[Table[q[n],
    {n, 1, 80}]]  (* A194907 *)

A194835 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(2).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Sep 03 2011

Keywords

Comments

See A194832 for a general discussion.

Examples

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

Crossrefs

Programs

  • Mathematica
    r = -Sqrt[2];
    t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
    f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]]  (* A194835 *)
    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}]] (* A194836 *)
    q[n_] := Position[p, n]; Flatten[Table[q[n],
     {n, 1, 80}]]  (* A194837 *)

A194841 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).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Sep 04 2011

Keywords

Comments

See A194832 for a general discussion.

Examples

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

Crossrefs

Programs

  • 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}]]   (* A194841 *)
    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}]]    (* A194842 *)
    q[n_] := Position[p, n]; Flatten[
     Table[q[n], {n, 1, 80}]]   (* A194843 *)

A194842 Rectangular array, by antidiagonals: row n gives the positions of n in the fractal sequence A194841; an interspersion.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 8, 9, 10, 7, 12, 14, 15, 11, 13, 17, 19, 21, 16, 18, 20, 23, 25, 27, 22, 24, 26, 28, 31, 33, 35, 29, 32, 34, 36, 30, 39, 42, 44, 37, 40, 43, 45, 38, 41, 48, 51, 54, 46, 49, 52, 55, 47, 50, 53, 58, 61, 64, 56, 59, 62, 65, 57, 60, 63, 66, 70, 73, 76
Offset: 1

Views

Author

Clark Kimberling, Sep 04 2011

Keywords

Comments

See A194832 and A194841.

Examples

			Northwest corner:
1...2...4...8...12..17..23
3...5...9...14..19..25..33
6...10..15..21..27..35..44
7...11..16..22..29..37..46
13..18..24..32..40..49..59
		

Crossrefs

Programs

  • 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}]]   (* A194841 *)
    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}]]    (* A194842 *)
    q[n_] := Position[p, n]; Flatten[
     Table[q[n], {n, 1, 80}]]   (* A194843 *)

A194868 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=-(1+sqrt(3))/2.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Sep 04 2011

Keywords

Comments

See A194832 for a general discussion.

Examples

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

Crossrefs

Programs

  • Mathematica
    r = -(1 + Sqrt[3])/2;
    t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
    f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@
    Sort[t[n], Less]], {n, 1, 20}]]  (* A194868 *)
    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}]] (* A194869 *)
    q[n_] := Position[p, n]; Flatten[Table[q[n],
    {n, 1, 80}]]   (* A194870 *)

A194836 Rectangular array, by antidiagonals: row n gives the positions of n in the fractal sequence A194835; an interspersion.

Original entry on oeis.org

1, 3, 2, 5, 4, 6, 9, 7, 10, 8, 13, 11, 14, 12, 15, 19, 16, 20, 17, 21, 18, 26, 23, 27, 24, 28, 25, 22, 33, 30, 35, 31, 36, 32, 29, 34, 42, 38, 44, 40, 45, 41, 37, 43, 39, 51, 47, 53, 49, 55, 50, 46, 52, 48, 54, 62, 57, 64, 59, 66, 61, 56, 63, 58, 65, 60, 74, 69, 76
Offset: 1

Views

Author

Clark Kimberling, Sep 03 2011

Keywords

Comments

Each pair of rows eventually intersperse.

Examples

			 Northwest corner:
1...3...5...9...13..19..26
2...4...7...11..16..23..30
6...10..14..20..27..35..44
8...12..17..24..31..40..49
15..21..28..36..45..55..66
18..25..32..41..50..61..73
		

Crossrefs

Programs

  • Mathematica
    r = -Sqrt[2];
    t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
    f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]]  (* A194835 *)
    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}]] (* A194836 *)
    q[n_] := Position[p, n]; Flatten[Table[q[n],
     {n, 1, 80}]]  (* A194837 *)
Showing 1-10 of 49 results. Next