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.

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A181116 Triangle T(n,k) read by rows. T(n,k) = A046643(A126988).

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 3, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 5, 3, 0, 1, 0, 0, 0, 1, 3, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 3, 1, 3, 1, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1
Offset: 1

Views

Author

Mats Granvik, Oct 04 2010

Keywords

Comments

Numerator in fraction A181116/A181117. A051731=(A181116/A181117)*(A181116/A181117).

Examples

			Triangle starts:
1,
1,1,
1,0,1,
3,1,0,1,
1,0,0,0,1,
1,1,1,0,0,1,
1,0,0,0,0,0,1,
5,3,0,1,0,0,0,1,
3,0,1,0,0,0,0,0,1,
1,1,0,0,1,0,0,0,0,1,
1,0,0,0,0,0,0,0,0,0,1,
3,1,3,1,0,1,0,0,0,0,0,1,
1,0,0,0,0,0,0,0,0,0,0,0,1,
1,1,0,0,0,0,1,0,0,0,0,0,0,1,
1,0,1,0,1,0,0,0,0,0,0,0,0,0,1,
		

Crossrefs

A181117 Triangle T(n,k) read by rows. T(n,k) = A046644(A126988).

Original entry on oeis.org

1, 2, 1, 2, 0, 1, 8, 2, 0, 1, 2, 0, 0, 0, 1, 4, 2, 2, 0, 0, 1, 2, 0, 0, 0, 0, 0, 1, 16, 8, 0, 2, 0, 0, 0, 1, 8, 0, 2, 0, 0, 0, 0, 0, 1, 4, 2, 0, 0, 2, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 16, 4, 8, 2, 0, 2, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 4, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 1
Offset: 1

Views

Author

Mats Granvik, Oct 04 2010

Keywords

Comments

Denominator in fraction A181116/A181117.

Examples

			Triangle starts:
1,
2,1,
2,0,1,
8,2,0,1,
2,0,0,0,1,
4,2,2,0,0,1,
2,0,0,0,0,0,1,
16,8,0,2,0,0,0,1,
8,0,2,0,0,0,0,0,1,
4,2,0,0,2,0,0,0,0,1,
2,0,0,0,0,0,0,0,0,0,1,
16,4,8,2,0,2,0,0,0,0,0,1,
2,0,0,0,0,0,0,0,0,0,0,0,1,
4,2,0,0,0,0,2,0,0,0,0,0,0,1,
4,0,2,0,2,0,0,0,0,0,0,0,0,0,1,
		

Crossrefs

A127168 Triangle read by rows: square of A126988.

Original entry on oeis.org

1, 4, 1, 6, 0, 1, 12, 4, 0, 1, 10, 0, 0, 0, 1, 24, 6, 4, 0, 0, 1, 14, 0, 0, 0, 0, 0, 1, 32, 12, 0, 4, 0, 0, 0, 1, 27, 0, 6, 0, 0, 0, 0, 0, 1, 40, 10, 0, 0, 4, 0, 0, 0, 0, 1, 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 72, 24, 12, 6, 0, 4, 0, 0, 0, 0, 0, 1, 26, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
Offset: 0

Views

Author

Gary W. Adamson, Jan 06 2007

Keywords

Comments

Row sums = A060640: (1, 5, 7, 17, 11, 35, 15, 49...) Left column = A038040, d(n)*n: (1, 4, 6, 12, 10, 24, 14, 32, 27, 40...). A127168 * A008683 = A018804, (1, 3, 5, 8, 9, 15...); where A008683 = the Mobius sequence.

Examples

			First few rows of the triangle are:
1;
4, 1;
6, 0, 1;
12, 4, 0, 1
10, 0, 0, 0, 1
24, 6, 4, 0, 0, 1
14, 0, 0, 0, 0, 0, 1;
32, 12, 0, 4, 0, 0, 0, 1;
...
		

Crossrefs

Extensions

a(20) = 1 inserted and more terms from Georg Fischer, May 31 2023

A127169 Triangle read by rows: cube of A126988.

Original entry on oeis.org

1, 6, 1, 9, 0, 1, 24, 6, 0, 1, 15, 0, 0, 0, 1, 54, 9, 6, 0, 0, 1, 21, 0, 0, 0, 0, 0, 1, 80, 24, 0, 6, 0, 0, 0, 1, 54, 0, 9, 0, 0, 0, 0, 0, 1, 90, 15, 0, 0, 6, 0, 0, 0, 0, 1
Offset: 1

Views

Author

Gary W. Adamson, Jan 06 2007

Keywords

Comments

Left column = A034718: (1, 6, 9, 24, 15, 54, 21...)

Examples

			First few rows of the triangle are:
[0] 1;
[1] 6, 1;
[2] 9, 0, 1;
[3] 24, 6, 0, 1;
[4] 15, 0, 0, 0, 1;
[5] 54, 9, 6, 0, 0, 1;
[6] 21, 0, 0, 0, 0, 0, 1;
[7] 80, 24, 0, 6, 0, 0, 0, 1;
[8] 54, 0, 9, 0, 0, 0, 0, 0, 1;
[9] 90, 15, 0, 0, 6, 0, 0, 0, 0, 1;
...
		

Crossrefs

Extensions

a(45), a(54) deleted by Georg Fischer, Jun 01 2023

A127332 A126988 * A002321.

Original entry on oeis.org

1, 2, 2, 3, 3, 3, 5, 4, 4, 5, 9, 1, 10, 8, 3, 7, 15, 3, 16, 2, 6, 17, 21, -6, 13, 19, 11, 8, 27, -5, 27, 10, 13, 28, 10, -10, 35, 31, 17, -6, 40, -3, 40, 20, -4, 40, 44, -18, 32, 18, 26, 23, 50, 4, 21, 0, 28, 54, 58, -45, 59, 53, 3, 19, 24, 11, 65, 37, 39, 1
Offset: 1

Views

Author

Gary W. Adamson, Jan 10 2007

Keywords

Examples

			a(6) = 3 = 6*1 + 3*0 + 2*(-1) + 0*(-1) + 0*(-2) + 1*(-1), where (6, 3, 2, 0, 0, 1) = row 6 of A126988.
		

Crossrefs

Programs

  • Mathematica
    Block[{nn = 70, m}, m = Table[Sum[MoebiusMu@k, {k, n}], {n, nn}]; Table[Total@ Array[m[[#]] If[Mod[n, #] == 0, n/#, 0] &, n], {n, nn}]] (* Michael De Vlieger, Jun 14 2018 *)
  • PARI
    lista(nn) = {mat = matrix(nn, nn, n, k, if (n % k, 0, n/k)); vec = matrix(nn, 1, n, k, if (k==1, mertens(n), 0)); res = (mat*vec); for (n = 1, nn, print1(res[n, 1], ", "););} \\ Michel Marcus, Sep 25 2013
    
  • PARI
    a(n) = sum(k=1, n, moebius(k / gcd(n, k)) * eulerphi(k) / eulerphi(k / gcd(n, k))); \\ Daniel Suteu, Jun 23 2018

Formula

M * V where M = A126988 as an infinite lower triangular matrix and V = the Mertens sequence, A002321 as a vector: [1, 0, -1, -1, -2, -1, ...].
a(n) = Sum_{q=1..n} c_q(n), where c_q(n) is the Ramanujan's sum function given in A054533. - Daniel Suteu, Jun 14 2018

Extensions

Corrected and extended by Michel Marcus, Sep 25 2013

A127445 Triangle defined by the matrix product A126988 * A127368, read by rows.

Original entry on oeis.org

1, 3, 0, 4, 2, 0, 7, 0, 3, 0, 6, 2, 3, 4, 0, 12, 4, 0, 0, 5, 0, 8, 2, 3, 4, 5, 6, 0, 15, 0, 9, 0, 5, 0, 7, 0, 13, 8, 0, 4, 5, 0, 7, 8, 0, 18, 4, 9, 8, 0, 0, 7, 0, 9, 0, 12, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0, 28, 8, 9, 0, 15, 0, 7, 0, 0, 0, 11
Offset: 1

Views

Author

Gary W. Adamson, Jan 14 2007

Keywords

Examples

			First few rows of the triangle are:
1;
3, 0;
4, 2, 0;
7, 0, 3, 0;
6, 2, 3, 4, 0;
12, 4, 0, 0, 5, 0;
8, 2, 3, 4, 5, 6, 0;
...
		

Crossrefs

Cf. A126988, A127368, A000217 (row sums), A000203 (column k=1).

Programs

Formula

T(n,k) = Sum_{j=k..n} A126988(n,j) * A127368(j,k), 1<=k<=n.

A134839 Triangle, n-th row = first n terms in n-th row of an array formed by A051731 * A126988(transform).

Original entry on oeis.org

1, 1, 3, 1, 2, 4, 1, 3, 3, 7, 1, 2, 3, 4, 6, 1, 3, 4, 6, 5, 12, 1, 2, 3, 4, 5, 6, 8, 1, 3, 3, 7, 5, 9, 7, 15, 1, 2, 4, 4, 5, 8, 7, 8, 13, 1, 3, 3, 6, 6, 9, 7, 12, 9, 18
Offset: 1

Views

Author

Gary W. Adamson, Nov 12 2007

Keywords

Comments

Right border = sigma(n), A000203: (1, 3, 4, 7, 6, 12, ...).
Row sums = A007437: (1, 4, 7, 14, 16, 31, 29, 50, ...).

Examples

			First few rows of the array:
  1,  2,  3,  4,  5,  6,  7, ...
  1,  3,  3,  6,  5,  9,  7, ...
  1,  2,  4,  4,  5,  8,  7, ...
  1,  3,  3,  7,  5,  9,  7, ...
  1,  2,  3,  4,  6,  6,  7, ...
  1,  3,  4,  6,  5, 12,  7, ...
  ...
First few rows of the triangle:
  1;
  1,  3;
  1,  2,  4;
  1,  3,  3,  7;
  1,  2,  3,  4,  6;
  1,  3,  4,  6,  5, 12;
  1,  2,  3,  4,  5,  6,  8;
  ...
		

Crossrefs

Formula

Given the array formed by A051731 * A126988(transform), the triangle by rows = first n terms of n-th row of the array.

A134840 Triangle, antidiagonals of an array formed by A051731 * A126988(transform).

Original entry on oeis.org

1, 1, 2, 1, 3, 3, 1, 2, 3, 4, 1, 3, 4, 6, 5, 1, 2, 3, 4, 5, 6, 1, 3, 3, 7, 5, 9, 7, 1, 2, 4, 4, 5, 8, 7, 8, 1, 3, 3, 6, 6, 9, 7, 12, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 3, 4, 7, 5, 12, 7, 14, 12, 15, 11
Offset: 1

Views

Author

Gary W. Adamson, Nov 12 2007

Keywords

Comments

Row sums = A069153: (1, 3, 7, 10, 19, 21, 35, 39, ...).

Examples

			First few rows of the array:
  1, 2, 3, 4, 5, 6, 7, ...
  1, 3, 3, 6, 5, 9, 7, ...
  1, 2, 4, 4, 5, 8, 7, ...
  1, 3, 3, 7, 5, 9, 7, ...
  1, 2, 3, 4, 6, 6, 7, ...
  ...
First few rows of the triangle:
  1;
  1, 2;
  1, 3, 3;
  1, 2, 3, 4;
  1, 3, 4, 6, 5;
  1, 2, 3, 4, 5, 6;
  1, 2, 3, 7, 5, 9, 7;
  1, 2, 4, 4, 5, 8, 7, 8;
  ...
		

Crossrefs

Formula

Triangle, antidiagonals of an array formed by A051731 * A126988(transform).

A134841 Triangle read by rows: first n terms of n-th row of an array formed by A126988 * A053731(transform).

Original entry on oeis.org

1, 2, 3, 3, 3, 4, 4, 6, 4, 7, 5, 5, 5, 5, 6, 6, 9, 8, 9, 6, 12, 7, 7, 7, 7, 7, 7, 8, 8, 12, 8, 14, 8, 12, 8, 15, 9, 9, 12, 9, 9, 12, 9, 9, 13, 10, 15, 10, 15, 12, 15, 10, 15, 10, 18
Offset: 0

Views

Author

Gary W. Adamson, Nov 12 2007

Keywords

Comments

Right border = sigma(n), A000203: (1, 3, 4, 7, 6, 12, ...).
Row sums = A001157: (1, 5, 10, 21, 26, 50, 50, ...).

Examples

			First few terms of the array:
  1,  1,  1,  1,  1,  1,  1, ...
  2,  3,  2,  3,  2,  3,  2, ...
  3,  3,  4,  3,  3,  4,  3, ...
  4,  6,  4,  7,  4,  6,  4, ...
  5,  5,  5,  5,  5,  6,  5, ...
  6,  9,  8,  9,  6, 12,  6, ...
  7,  7,  7,  7,  7,  7,  8, ...
  ...
First few rows of the triangle:
  1;
  2,  3;
  3,  3,  4;
  4,  6,  4,  7;
  5,  5,  5,  5,  6;
  6,  9,  8,  9,  6, 12;
  7,  7,  7,  7,  7,  7,  8,
  ...
		

Crossrefs

A141674 Triangle T(n,m) read by rows: T(n,m) = sigma_0(n) * A126988(n,m).

Original entry on oeis.org

1, 4, 2, 6, 0, 2, 12, 6, 0, 3, 10, 0, 0, 0, 2, 24, 12, 8, 0, 0, 4, 14, 0, 0, 0, 0, 0, 2, 32, 16, 0, 8, 0, 0, 0, 4, 27, 0, 9, 0, 0, 0, 0, 0, 3, 40, 20, 0, 0, 8, 0, 0, 0, 0, 4, 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 72, 36, 24, 18, 0, 12, 0, 0, 0, 0, 0, 6, 26, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 56, 28, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 4
Offset: 1

Views

Author

Roger L. Bagula and Gary W. Adamson, Sep 06 2008

Keywords

Comments

Row sums are {1, 6, 8, 21, 12, 48, 16, 60, 39, 72}.

Examples

			Triangle begins
  { 1},
  { 4,  2},
  { 6,  0,  2},
  {12,  6,  0,  3},
  {10,  0,  0,  0,  2},
  {24, 12,  8,  0,  0,  4},
  {14,  0,  0,  0,  0,  0,  2},
  {32, 16,  0,  8,  0,  0,  0,  4},
  {27,  0,  9,  0,  0,  0,  0,  0,  3},
  {40, 20,  0,  0,  8,  0,  0,  0,  0,  4}
		

Crossrefs

Cf. A126988.

Programs

  • Mathematica
    t[n_, m_] = DivisorSigma[0, n]*If[m == 1, n, If[Mod[n, m] == 0, n/m, 0]]; Table[Table[t[n, m], {m, 1, n}], {n, 1, 10}]; Flatten[%]

Formula

T(n,m) = sigma_0(n) * A126988(n,m).
T(n,m) = sigma_0(n) * if(m = 1, n, if(n mod m = 0, n/m, 0)).

Extensions

Edited by the Associate Editors of the OEIS, Jun 10 2018
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