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 11-19 of 19 results.

A115372 Decimal expansion of first zero of BesselJ(4,z).

Original entry on oeis.org

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

Views

Author

Eric W. Weisstein, Jan 21 2006

Keywords

Examples

			7.5883424345038043850...
		

Crossrefs

Programs

A115373 Decimal expansion of first zero of BesselJ(5,z).

Original entry on oeis.org

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

Views

Author

Eric W. Weisstein, Jan 21 2006

Keywords

Examples

			8.7714838159599540191...
		

Crossrefs

Programs

A259616 Decimal expansion of J'_1(1), the first root of the derivative of the Bessel function J_1.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jul 01 2015

Keywords

Comments

Also root of the equation J_0(x) = J_2(x). - Vaclav Kotesovec, Jul 01 2015

Examples

			1.8411837813406593026436295136444433224361270390968192643504677429242292...
		

Crossrefs

Cf. A115369 J'_0(1), A259617 J'_2(1), A259618 J'_3(1), A259619 J'_4(1), A259620 J'_5(1).

Programs

  • Mathematica
    FindRoot[D[BesselJ[1, x], x] == 0, {x, 2}, WorkingPrecision -> 105] // Last // Last // RealDigits // First

A259617 Decimal expansion of J'_2(1), the first root of the derivative of the Bessel function J_2.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jul 01 2015

Keywords

Examples

			3.054236928227140322755932091148560897641496760529945919816437566658545...
		

Crossrefs

Cf. A115369 J'_0(1), A259616 J'_1(1), A259618 J'_3(1), A259619 J'_4(1), A259620 J'_5(1).

Programs

  • Mathematica
    FindRoot[D[BesselJ[2, x], x] == 0, {x, 3}, WorkingPrecision -> 105] // Last // Last // RealDigits // First

A259618 Decimal expansion of J'_3(1), the first root of the derivative of the Bessel function J_3.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jul 01 2015

Keywords

Examples

			4.2011889412105284961878552974567121879446032135899833521760017910209584...
		

Crossrefs

Cf. A115369 J'_0(1), A259616 J'_1(1), A259617 J'_2(1), A259619 J'_4(1), A259620 J'_5(1).

Programs

  • Mathematica
    FindRoot[D[BesselJ[3, x], x] == 0, {x, 4}, WorkingPrecision -> 104] // Last // Last // RealDigits // First

A259619 Decimal expansion of J'_4(1), the first root of the derivative of the Bessel function J_4.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jul 01 2015

Keywords

Examples

			5.317553126083994350363355558188919214766698286220102866220429337604059...
		

Crossrefs

Cf. A115369 J'_0(1), A259616 J'_1(1), A259617 J'_2(1), A259618 J'_3(1), A259620 J'_5(1).

Programs

  • Mathematica
    FindRoot[D[BesselJ[4, x], x] == 0, {x, 5}, WorkingPrecision -> 104] // Last // Last // RealDigits // First

A259620 Decimal expansion of J'_5(1), the first root of the derivative of the Bessel function J_5.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jul 01 2015

Keywords

Examples

			6.41561637570024028283981471908792403810900056520772077867494762732288...
		

Crossrefs

Cf. A115369 J'_0(1), A259616 J'_1(1), A259617 J'_2(1), A259618 J'_3(1), A259619 J'_4(1).

Programs

  • Mathematica
    FindRoot[D[BesselJ[5, x], x] == 0, {x, 6}, WorkingPrecision -> 105] // Last // Last // RealDigits // First

A245461 Decimal expansion of constant in the Rayleigh criterion: first zero of J_1, divided by Pi.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

The angular resolution (diffraction limit), in radians, is this constant times the wavelength of the light used divided by the aperture diameter. That is: objects closer than this angle cannot be resolved as separate objects.
Note that the small angle approximation sin(theta) =~ theta can be used. Also, a commonly used approximation to this constant is 1.220. - John W. Nicholson, Jul 29 2014
For example, a radio telescope with a 300-meter aperture observing at the hydrogen line (21.106... cm) can distinguish objects at most 0.04916... degrees apart. - Charles R Greathouse IV, Mar 08 2018

Examples

			1.21966989126650445492653884746525517787935933077511...
		

Crossrefs

Programs

Formula

A221210 Decimal expansion of the abscissa of the half width of the Airy function.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Feb 21 2013

Keywords

Comments

In optics, the Airy function is the amplitude pattern of light shining through a circular hole, which gives (in the Fraunhofer limit of diffraction theory) an amplitude proportional to J_1(z)/z, where J_1 is the Bessel function of order 1, and where z is the radial coordinate. The Airy disk is the intensity, the square of the amplitude, proportional to I=(J_1(z)/z)^2, with the first zero at A115369. The peak is at I(0)=1/4, so the half width is defined by I(zhalf)=1/8, which gives zhalf = 1.6163399483.., defining the sequence of digits.

Crossrefs

Cf. A245461.

Programs

  • Mathematica
    z /. FindRoot[ BesselJ[1, z]^2/z^2 == 1/8 , {z, 1}, WorkingPrecision -> 76] // RealDigits // First (* Jean-François Alcover, Feb 21 2013 *)
  • PARI
    solve(x=1,2,8*besselj(1,x)^2-x^2) \\ Charles R Greathouse IV, Feb 19 2014
Previous Showing 11-19 of 19 results.