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.

Previous Showing 11-20 of 20 results.

A143469 Triangle read by rows, A000012 * A143315 * A128407, 1<=k<=1.

Original entry on oeis.org

1, 4, -1, 9, -1, -1, 16, -4, -1, 0, 25, -4, -1, 0, -1, 36, -9, -4, 0, -1, 1, 49, -9, -4, 0, -1, 1, -1, 64, -16, -4, 0, -1, 1, -1, 0, 81, -16, -9, 0, -1, 1, -1, 0, 0, 100, -25, -9, 0, -4, 1, -1, 0, 0, 1, 121, -25, -9, 0, -4, 1, -1, 0, 0, 1, -1, 144, -36, -16, 0, -4, 4, -1, 0, 0, 1, -1, 0
Offset: 1

Views

Author

Gary W. Adamson, Aug 17 2008

Keywords

Comments

Row sums = A018805: (1, 3, 7, 11, 19, 23, 35,...).
Right border = mu(n), A008683.

Examples

			First few rows of the triangle =
1;
4, -1;
9, -1, -1;
16, -4, -1, 0;
25, -4, -1, 0, -1;
36, -9, -4, 0, -1, 1;
49, -9, -4, 0, -1, 1, -1;
...
		

Crossrefs

Extensions

a(9) corrected and more terms from Georg Fischer, Aug 14 2023

A128431 Triangle read by rows: A054521 * A128407.

Original entry on oeis.org

1, 1, 0, 1, -1, 0, 1, 0, -1, 0, 1, -1, -1, 0, 0, 1, 0, 0, 0, -1, 0, 1, -1, -1, 0, -1, 1, 0, 1, 0, -1, 0, -1, 0, -1, 0, 1, -1, 0, 0, -1, 0, -1, 0, 0, 1, 0, -1, 0, 0, 0, -1, 0, 0, 0
Offset: 1

Views

Author

Gary W. Adamson, Mar 03 2007

Keywords

Comments

Row sums = A112399: (1, 1, 0, 0, -1, 0, -1, -2, -2, -1, ...).

Examples

			First few rows of the triangle:
  1;
  1,  0;
  1, -1,  0;
  1,  0, -1,  0;
  1, -1, -1,  0,  0;
  1,  0,  0,  0, -1,  0;
  1, -1, -1,  0, -1,  1,  0;
		

Crossrefs

Formula

A054521 * A128407 as infinite lower triangular matrices.

A128432 Triangle read by rows: A128407 * A054521.

Original entry on oeis.org

1, -1, 0, -1, -1, 0, 0, 0, 0, 0, -1, -1, -1, -1, 0, 1, 0, 0, 0, 1, 0, -1, -1, -1, -1, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0
Offset: 1

Views

Author

Gary W. Adamson, Mar 03 2007

Keywords

Comments

Row sums = A023900: (1, -1, -2, 0, -4, 2, -6, ...) Left border = mu(n), A008683.

Examples

			First few rows of the triangle:
   1;
  -1,  0;
  -1, -1,  0;
   0,  0,  0,  0;
  -1, -1, -1, -1,  0;
   1,  0,  0,  0,  1,  0;
  -1, -1, -1, -1, -1, -1,  0;
   0,  0,  0,  0,  0,  0,  0,  0;
  ...
		

Crossrefs

Formula

A128407 * A054521 as infinite lower triangular matrices.

A143352 Triangle read by rows, A051731 * A054524 = (A051731)^2 * A128407; 1<=k<=n.

Original entry on oeis.org

1, 2, -1, 2, 0, -1, 3, -2, 0, 0, 2, 0, 0, 0, -1, 4, -2, -2, 0, 0, 1, 2, 0, 0, 0, 0, 0, -1, 4, -3, 0, 0, 0, 0, 0, 0, 3, 0, -2, 0, 0, 0, 0, 0, 0, 4, -2, 0, 0, -2, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 6, -4, -3, 0, 0, 2, 0, 0, 0, 0, 0, 0, 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

Gary W. Adamson, Aug 10 2008

Keywords

Comments

Left border = d(n), A000010.
Right border = mu(n), A008683.
Row sums = 1.

Examples

			First few rows of the triangle =
1;
2, -1;
2, 0, -1;
3, -2, 0, 0;
2, 0, 0, 0, -1
4, -2, -2, 0, 0, 1;
2, 0, 0, 0, 0, 0, -1;
4, -3, 0, 0, 0, 0, 0, 0;
3, 0, -2, 0, 0, 0, 0, 0, 0;
4, -2, 0, 0, -2, 0, 0, 0, 0, 1;
...
		

Crossrefs

Formula

Triangle read by rows, A051731 * A054524 = (A051731)^2 * A128407; 1<=k<=n

A054524 Triangle T(n,k): T(n,k) = mu(k) if k divides n, T(n,k)=0 otherwise (n >= 1, 1<=k<=n).

Original entry on oeis.org

1, 1, -1, 1, 0, -1, 1, -1, 0, 0, 1, 0, 0, 0, -1, 1, -1, -1, 0, 0, 1, 1, 0, 0, 0, 0, 0, -1, 1, -1, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, -1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, -1, -1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, -1
Offset: 1

Views

Author

N. J. A. Sloane, Apr 09 2000

Keywords

Crossrefs

Programs

  • Mathematica
    Clear[t]; t[n_, 1] = 1; t[n_, k_] := t[n, k] = If[k == 1, 1, If[n == k, -Sum[t[n, k - i], {i, 1, k - 1}], If[n > k, t[n - k, k], 0]]]; Flatten[Table[t[n, k], {n, 13}, {k, n}]] (* Mats Granvik, Feb 12 2012 *)
    Table[If[Mod[n,k]==0,MoebiusMu[k],0],{n,20},{k,n}]//Flatten (* Harvey P. Dale, Mar 29 2023 *)

Formula

A127512 Triangle read by rows: T(n,k)= mobius(n)*binomial(n-1,k-1).

Original entry on oeis.org

1, -1, -1, -1, -2, -1, 0, 0, 0, 0, -1, -4, -6, -4, -1, 1, 5, 10, 10, 5, 1, -1, -6, -15, -20, -15, -6, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 9, 36, 84, 126, 126, 84, 36, 9, 1, -1, -10, -45, -120, -210, -252, -210, -120, -45, -10, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 1

Views

Author

Gary W. Adamson, Jan 17 2007

Keywords

Comments

Could also be defined as the matrix product of A128407 and A007318.
A013929 gives the indices of rows that are all zeros. - Michel Marcus, Feb 15 2022

Examples

			First few rows of the triangle:
   1;
  -1, -1;
  -1, -2, -1;
   0,  0,  0,  0;
  -1, -4, -6, -4, -1;
   1,  5, 10, 10,  5, 1;
  ...
		

Crossrefs

Cf. A007318, A008683, A013929, A127511 (row sums).
Cf. A127514 (P*M).

Programs

  • Maple
    A127512 := proc(n,k)
        numtheory[mobius](n)*binomial(n-1,k-1) ;
    end proc:
    seq(seq( A127512(n,k),k=1..n),n=1..10) ; # R. J. Mathar, Aug 15 2022
  • Mathematica
    T[n_,k_]:= MoebiusMu[n]*Binomial[n-1,k-1];Table[T[n,k],{n,12},{k,n}]//Flatten (* James C. McMahon, Jan 02 2025 *)
  • PARI
    row(n) = my(M = matrix(n, n, i, j, if (i==j, moebius(i))), P = matrix(n, n, i, j, binomial(i-1, j-1))); vector(n, k, (M*P)[n, k]); \\ Michel Marcus, Feb 15 2022

Formula

T(n,k) = mu(n)*binomial(n-1,k-1) = A008683(n)*A007318(n-1,k-1). - R. J. Mathar, Aug 15 2022

Extensions

Edited by N. J. A. Sloane, Sep 25 2008
NAME simplified by R. J. Mathar, Aug 15 2022

A128409 Triangle read by rows: A000012 * A128408 as infinite lower triangular matrices.

Original entry on oeis.org

1, 0, -1, -1, -1, -1, -1, -1, -1, 0, -2, -1, -1, 0, -1, -1, 0, 0, 0, -1, 1, -2, 0, 0, 0, -1, 1, -1, -2, 0, 0, 0, -1, 1, -1, 0, -2, 0, 0, 0, -1, 1, -1, 0, 0, -1, 1, 0, 0, 0, 1, -1, 0, 0, 1, -2, 1, 0, 0, 0, 1, -1, 0, 0, 1, -1, -2, 1, 0, 0, 0, 1, -1, 0, 0, 1, -1, 0, -3, 1, 0, 0, 0, 1, -1, 0, 0, 1, -1, 0, -1
Offset: 1

Views

Author

Gary W. Adamson, Mar 01 2007

Keywords

Comments

Left border = the Mertens sequence: A002321: (1, 0, -1, -1, -2, ...).
Right border = mu(n), A008683: (1, -1, -1, 0, -1, 1, -1, ...).
Row sums = A062563: (1, -1, -3, -3, -5, -1, -3, ...).

Examples

			First few rows of the triangle:
   1;
   0, -1;
  -1, -1, -1;
  -1, -1, -1,  0;
  -2, -1, -1,  0, -1;
  -1,  0,  0,  0, -1,  1;
  -2,  0,  0,  0, -1,  1, -1;
  ...
		

Crossrefs

Extensions

Previous a(51) = 0 removed and more terms from Georg Fischer, Jun 08 2023

A143728 Triangle read by rows: termwise product of mu(n) and n-th row of A127368.

Original entry on oeis.org

1, 1, 0, 1, -2, 0, 1, 0, -3, 0, 1, -2, -3, 0, 0, 1, 0, 0, 0, -5, 0, 1, -2, -3, 0, -5, 6, 0, 1, 0, -3, 0, -5, 0, -7, 0, 1, -2, 0, 0, -5, 0, -7, 0, 0, 1, 0, -3, 0, 0, 0, -7, 0, 0, 0, 1, -2, -3, 0, -5, 6, -7, 0, 0, 10, 0, 1, 0, 0, 0, -5, 0, -7, 0, 0, 0, -11, 0, 1, -2, -3, 0, -5, 6, -7, 0, 0, 10, -11, 0, 0
Offset: 1

Views

Author

Gary W. Adamson, Aug 30 2008

Keywords

Comments

The operation A127368 * A128407 forms the termwise product of mu(n) and the n-th row of A127368: deleting all squares and changing the sign of primes to (-1).
Row sums = A143729: (1, 1, -1, -2, -4, -4, -3, -14, ...)

Examples

			First few terms of the triangle:
  1;
  1,  0;
  1, -2,  0;
  1,  0, -3,  0;
  1, -2, -3,  0,  0;
  1,  0,  0,  0, -5,  0;
  1, -2, -3,  0, -5,  6,  0;
  1,  0, -3,  0, -5,  0, -7,  0;
  ...
Example: row 7 = (1, -2, -3, 0, -5, 6, 0). We take row 7 of triangle A127368 which records the relative primes of 7 as (1, 2, 3, 4, 5, 6, 0). Applying the termwise product of the first 7 terms of mu(k): (1, -1, -1, 0, -1, 1, -1), we get (1, -2, -3, 0, -5, 6, 0), noting that the "4" has been deleted.
		

Crossrefs

Formula

Triangle read by rows, A127368 * A128407, 1 <= k <= n; T(n,k) = {1<=k<=n, gcd(k,n)=1} * mu(k).

Extensions

Partially edited by N. J. A. Sloane, Jan 05 2009
a(66) = 0 inserted by Georg Fischer, Jun 05 2023

A128410 A128408 * A000012.

Original entry on oeis.org

1, -2, -1, -2, -1, -1, 0, 0, 0, 0, -2, -1, -1, -1, -1, 4, 3, 2, 1, 1, 1, -2, -1, -1, -1, -1, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 3, 2, 2, 2, 1, 1, 1, 1, 1
Offset: 1

Views

Author

Gary W. Adamson, Mar 01 2007

Keywords

Comments

Left border = A008966: (1, -2, -2, 0, -2, 4, -2, 0, 0, 4, ...). Row sums = A063441: (1, -3, -4, 0, -6, 12, ...) A128409 = A000012 * A128408.

Examples

			First few rows of the triangle:
   1;
  -2, -1;
  -2, -1, -1;
   0,  0,  0,  0;
  -2, -1, -1, -1, -1;
   4,  3,  2,  1,  1,  1;
  -2, -1, -1, -1, -1, -1, -1;
  ...
		

Crossrefs

Formula

A128408 * A000012 as infinite lower triangular matrices. Partial row sums of A128408 starting from the right.

A128430 Triangle read by rows: A054524 * A000012.

Original entry on oeis.org

1, 0, -1, 0, -1, -1, 0, -1, 0, 0, 0, -1, -1, -1, -1, 0, -1, 0, 1, 1, 1, 0, -1, -1, -1, -1, -1, -1, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 1, 1, 1, 1, 1
Offset: 1

Views

Author

Gary W. Adamson, Mar 02 2007

Keywords

Comments

Right border = mu(n), A008683. Row sums = A023900: (1, -1, -2, -1, -4, 2, -6, -1, ...). A054524 = A051731 * A128407.

Examples

			First few rows of the triangle:
  1;
  0, -1;
  0, -1, -1;
  0, -1,  0,  0;
  0, -1, -1, -1, -1;
  0, -1,  0,  1,  1,  1;
  0, -1, -1, -1, -1, -1, -1;
  0, -1,  0,  0,  0,  0,  0,  0;
  ...
		

Crossrefs

Formula

A054524 * A000012 as infinite lower triangular matrices.
Previous Showing 11-20 of 20 results.