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 10 results.

A175472 Decimal expansion of the absolute value of the abscissa of the local maximum of the Gamma function in the interval [ -1,0].

Original entry on oeis.org

5, 0, 4, 0, 8, 3, 0, 0, 8, 2, 6, 4, 4, 5, 5, 4, 0, 9, 2, 5, 8, 2, 6, 9, 3, 0, 4, 5, 3, 3, 3, 0, 2, 4, 9, 8, 9, 5, 5, 3, 8, 5, 1, 8, 2, 3, 6, 8, 5, 7, 9, 8, 4, 5, 1, 7, 7, 2, 6, 9, 5, 8, 4, 5, 0, 9, 5, 9, 3, 8, 3, 3, 7, 1, 3, 4, 7, 8, 8, 6, 4, 6, 2, 5, 6, 4, 4, 7, 9, 3, 8, 1, 5, 1, 3, 6, 5, 2, 5, 4, 6, 8, 0, 1, 9
Offset: 0

Views

Author

R. J. Mathar, May 25 2010

Keywords

Comments

Also the location of the zero of the digamma function in the same interval.

Examples

			Gamma(-0.5040830082644554092582693045...) = -3.5446436111550050891219639933..
		

References

  • Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 44, page 427.

Crossrefs

Programs

  • Mathematica
    x /. FindRoot[ PolyGamma[0, x] == 0, {x, -1/2}, WorkingPrecision -> 105] // Abs // RealDigits // First  (* Jean-François Alcover, Jan 21 2013 *)
  • PARI
    solve(x=.5,.6,psi(-x)) \\ Charles R Greathouse IV, Jul 19 2013

A175473 Decimal expansion of the absolute value of the abscissa of the local minimum of the Gamma function in the interval [ -2,-1].

Original entry on oeis.org

1, 5, 7, 3, 4, 9, 8, 4, 7, 3, 1, 6, 2, 3, 9, 0, 4, 5, 8, 7, 7, 8, 2, 8, 6, 0, 4, 3, 6, 9, 0, 4, 3, 4, 6, 1, 2, 6, 5, 5, 0, 4, 0, 8, 5, 9, 1, 1, 6, 8, 4, 6, 1, 4, 9, 9, 3, 0, 1, 4, 2, 5, 6, 8, 7, 9, 7, 0, 2, 0, 3, 4, 4, 3, 9, 6, 5, 1, 4, 0, 4, 8, 1, 0, 4, 7, 3, 2, 3, 9, 8, 2, 5, 1, 8, 8, 5, 6, 2, 8, 1, 8, 7, 7, 0
Offset: 1

Views

Author

R. J. Mathar, May 25 2010

Keywords

Comments

Also the location of the zero of the digamma function in the same interval.

Examples

			Gamma(-1.5734984731623904587782860437..) = 2.3024072583396801358235820396..
		

References

  • Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 44, page 427.

Crossrefs

Programs

  • Mathematica
    x /. FindRoot[ PolyGamma[0, x] == 0, {x, -3/2}, WorkingPrecision -> 110] // Abs // RealDigits // First // Take[#, 105]& (* Jean-François Alcover, Jan 21 2013 *)
  • PARI
    solve(x=1.5,1.6,psi(-x)) \\ Charles R Greathouse IV, Jul 19 2013

A256681 Decimal expansion of the [negated] abscissa of the Gamma function local minimum in the interval [-4,-3].

Original entry on oeis.org

3, 6, 3, 5, 2, 9, 3, 3, 6, 6, 4, 3, 6, 9, 0, 1, 0, 9, 7, 8, 3, 9, 1, 8, 1, 5, 6, 6, 9, 4, 6, 0, 1, 7, 7, 1, 3, 9, 4, 8, 4, 2, 3, 8, 6, 1, 1, 9, 3, 5, 3, 0, 7, 0, 8, 7, 4, 8, 4, 7, 9, 0, 0, 6, 7, 5, 5, 8, 9, 5, 9, 7, 8, 3, 8, 4, 9, 8, 8, 9, 6, 6, 4, 8, 4, 0, 5, 5, 8, 3, 9, 9, 8, 4, 6, 0, 0, 8, 0, 3, 6, 8, 3, 3
Offset: 1

Views

Author

Jean-François Alcover, Apr 08 2015

Keywords

Examples

			Gamma(-3.6352933664369010978391815669460177139484238611935307...)
= 0.245127539834366250438230088857478287588513028833668283...
		

Crossrefs

Programs

  • Mathematica
    digits = 104; x0 = x /. FindRoot[PolyGamma[x] == 0, {x, -7/2}, WorkingPrecision -> digits + 5]; RealDigits[x0, 10, digits] // First

Formula

Solution to PolyGamma(x) = 0 in the interval [-4,-3].

A344964 Decimal expansion of the sum of the reciprocals of the squares of the zeros of the digamma function.

Original entry on oeis.org

5, 2, 6, 7, 9, 8, 0, 1, 2, 4, 3, 5, 2, 3, 9, 7, 9, 8, 3, 7, 3, 5, 6, 2, 1, 6, 3, 6, 2, 9, 3, 3, 1, 9, 7, 9, 4, 3, 1, 6, 2, 6, 6, 8, 4, 3, 8, 7, 0, 0, 2, 5, 0, 5, 6, 3, 5, 7, 5, 0, 8, 0, 2, 6, 1, 1, 2, 2, 8, 8, 2, 0, 4, 9, 0, 5, 3, 5, 9, 2, 9, 1, 1, 6, 2, 1, 4
Offset: 1

Views

Author

Amiram Eldar, Jun 03 2021

Keywords

Comments

The sum is Sum_{k>=0} 1/x_k^2, where x_k is the k-th zero of the digamma function, i.e., root of psi(x) = 0: x_0 = 1.461632... (A030169) is the only positive root, x_1 = -0.504083... (A175472), etc.

Examples

			5.26798012435239798373562163629331979431626684387002...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Pi^2/2 + EulerGamma^2, 10, 100][[1]]

Formula

Equals Pi^2/2 + gamma^2 = A102753 + A155969, where gamma is Euler's constant (A001620).

A344965 Decimal expansion of the sum of the reciprocals of the cubes of the zeros of the digamma function (negated).

Original entry on oeis.org

7, 8, 4, 8, 9, 8, 8, 2, 6, 2, 8, 0, 4, 5, 0, 6, 3, 0, 4, 8, 9, 8, 8, 3, 7, 3, 2, 7, 1, 6, 0, 5, 5, 0, 6, 7, 1, 1, 0, 1, 6, 4, 1, 2, 7, 9, 1, 1, 6, 3, 8, 0, 3, 2, 9, 2, 3, 2, 5, 3, 0, 0, 3, 4, 9, 8, 6, 4, 6, 7, 5, 0, 5, 8, 0, 6, 0, 1, 0, 3, 4, 4, 2, 7, 6, 1, 6
Offset: 1

Views

Author

Amiram Eldar, Jun 03 2021

Keywords

Comments

The sum is Sum_{k>=0} 1/x_k^3, where x_k is the k-th zero of the digamma function, i.e., root of psi(x) = 0: x_0 = 1.461632... (A030169) is the only positive root, x_1 = -0.504083... (A175472), etc.

Examples

			-7.84898826280450630489883732716055067110164127911638...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[EulerGamma*Pi^2/2 + 4*Zeta[3]  + EulerGamma^3, 10, 100][[1]]

Formula

Equals -gamma*Pi^2/2 - 4*zeta(3) - gamma^3, where gamma is Euler's constant (A001620).

A344966 Decimal expansion of the sum of the reciprocals of the fourth powers of the zeros of the digamma function.

Original entry on oeis.org

1, 5, 9, 0, 1, 8, 4, 7, 0, 3, 3, 2, 2, 3, 4, 9, 1, 5, 6, 9, 7, 2, 0, 8, 4, 5, 5, 7, 3, 5, 8, 4, 2, 5, 1, 7, 6, 5, 1, 9, 2, 5, 6, 6, 7, 2, 6, 4, 3, 4, 0, 2, 0, 4, 1, 0, 5, 7, 5, 7, 1, 6, 7, 9, 6, 5, 2, 1, 0, 5, 3, 8, 3, 8, 8, 6, 4, 6, 8, 5, 7, 8, 8, 9, 3, 2, 4
Offset: 2

Views

Author

Amiram Eldar, Jun 03 2021

Keywords

Comments

The sum is Sum_{k>=0} 1/x_k^4, where x_k is the k-th zero of the digamma function, i.e., root of psi(x) = 0: x_0 = 1.461632... (A030169) is the only positive root, x_1 = -0.504083... (A175472), etc.

Examples

			15.90184703322349156972084557358425176519256672643402...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Pi^4/9 + 2*EulerGamma^2*Pi^2/3 + 4*EulerGamma*Zeta[3] + EulerGamma^4, 10, 100][[1]]

Formula

Equals Pi^4/9 + 2*gamma^2*Pi^2/3 + 4*gamma*zeta(3) + gamma^4, where gamma is Euler's constant (A001620).

A344967 Decimal expansion of Sum_{k>=0} 1/(x_k^2 - 1), where x_k is the k-th zero of the digamma function.

Original entry on oeis.org

7, 1, 3, 4, 9, 4, 7, 2, 2, 1, 0, 9, 9, 6, 8, 1, 6, 7, 6, 9, 9, 3, 3, 5, 9, 4, 4, 4, 1, 3, 3, 3, 5, 6, 3, 6, 6, 5, 5, 3, 1, 8, 9, 3, 9, 5, 8, 5, 1, 2, 9, 5, 0, 5, 9, 4, 5, 8, 8, 7, 0, 1, 6, 5, 8, 1, 0, 4, 7, 2, 4, 0, 7, 9, 2, 1, 6, 8, 6, 8, 6, 0, 6, 1, 8, 7, 4
Offset: 0

Views

Author

Amiram Eldar, Jun 03 2021

Keywords

Comments

The zeros of the digamma function, i.e., the roots of psi(x) = 0 are x_0 = 1.461632... (A030169), the only positive root, x_1 = -0.504083... (A175472), etc.

Examples

			0.71349472210996816769933594441333563665531893958512...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Pi^2/(12*EulerGamma) + EulerGamma/2 - 1, 10, 100][[1]]

Formula

Equals Pi^2/(12*gamma) + gamma/2 - 1, where gamma is Euler's constant (A001620).

A344968 Decimal expansion of Sum_{k>=0} 1/(x_k^2 - x_k), where x_k is the k-th zero of the digamma function.

Original entry on oeis.org

3, 4, 2, 6, 9, 8, 9, 4, 4, 4, 2, 1, 9, 9, 3, 6, 3, 3, 5, 3, 9, 8, 6, 7, 1, 8, 8, 8, 8, 2, 6, 6, 7, 1, 2, 7, 3, 3, 1, 0, 6, 3, 7, 8, 7, 9, 1, 7, 0, 2, 5, 9, 0, 1, 1, 8, 9, 1, 7, 7, 4, 0, 3, 3, 1, 6, 2, 0, 9, 4, 4, 8, 1, 5, 8, 4, 3, 3, 7, 3, 7, 2, 1, 2, 3, 7, 4
Offset: 1

Views

Author

Amiram Eldar, Jun 03 2021

Keywords

Comments

The zeros of the digamma function, i.e., the roots of psi(x) = 0 are x_0 = 1.461632... (A030169), the only positive root, x_1 = -0.504083... (A175472), etc.

Examples

			3.42698944421993633539867188882667127331063787917025...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Pi^2/(6*EulerGamma) + EulerGamma, 10, 100][[1]]

Formula

Equals Pi^2/(6*gamma) + gamma, where gamma is Euler's constant (A001620).

A257433 Decimal expansion of the smallest negative real root of the equation Gamma(x) = -1 (negated).

Original entry on oeis.org

2, 4, 5, 7, 0, 2, 4, 7, 3, 8, 2, 2, 0, 8, 0, 0, 6, 2, 3, 0, 3, 9, 4, 5, 4, 1, 4, 7, 6, 5, 1, 1, 7, 9, 5, 4, 3, 2, 3, 6, 5, 9, 7, 9, 0, 9, 0, 3, 3, 7, 8, 4, 4, 2, 0, 9, 6, 4, 7, 9, 4, 4, 9, 5, 2, 8, 0, 6, 1, 2, 6, 3, 4, 2, 6, 0, 4, 9, 4, 9, 6, 1, 7, 0, 2, 3, 7, 0, 2, 9, 2, 6, 5, 5, 7, 2, 8, 2, 0, 6, 6, 1, 8, 3
Offset: 1

Views

Author

Jean-François Alcover, Apr 23 2015

Keywords

Examples

			-2.45702473822080062303945414765117954323659790903378442...
		

Crossrefs

Programs

  • Mathematica
    x1 = x /. FindRoot[Gamma[x] == -1, {x, -5/2}, WorkingPrecision -> 104]; RealDigits[x1] // First

Formula

-3 < A257434 = -2.747682... < A175474 = -2.61072... < A257433 = -2.457024... < -2.

A257434 Decimal expansion of the second smallest negative real root of the equation Gamma(x) = -1 (negated).

Original entry on oeis.org

2, 7, 4, 7, 6, 8, 2, 6, 4, 6, 7, 2, 7, 4, 1, 2, 6, 0, 1, 3, 9, 1, 4, 8, 8, 4, 8, 2, 6, 9, 1, 4, 9, 9, 6, 9, 5, 8, 6, 1, 6, 3, 9, 3, 9, 5, 1, 3, 2, 3, 5, 5, 5, 1, 2, 0, 5, 2, 2, 9, 9, 1, 4, 8, 1, 1, 2, 5, 3, 9, 0, 6, 7, 6, 4, 5, 5, 5, 0, 0, 6, 0, 4, 1, 9, 9, 7, 8, 6, 6, 4, 0, 0, 6, 6, 4, 5, 8, 3, 7, 3
Offset: 1

Views

Author

Jean-François Alcover, Apr 23 2015

Keywords

Examples

			-2.747682646727412601391488482691499695861639395132355512...
		

Crossrefs

Programs

  • Mathematica
    x2 = x /. FindRoot[Gamma[x] == -1, {x, -8/3}, WorkingPrecision -> 101]; RealDigits[x2] // First

Formula

-3 < A257434 = -2.747682... < A175474 = -2.61072... < A257433 = -2.457024... < -2.
Showing 1-10 of 10 results.