A213610 Decimal expansion of the characteristic impedance of vacuum in SI units as defined before 20 May 2019.

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

Offset

3,1

Comments

Denoted Z_0, this is a function of assigned metrological constants. Regarding these, see A003678 for general context notes, references and links. - Stanislav Sykora, Jun 16 2012

Links

Table of n, a(n) for n=3..107.

Wikipedia, Impedance of free space

Formula

Z_0 = [magnetic_permeability_of_vacuum]*[speed_of_light_in_vacuum] = 10^-6 * A019694 * A003678 = Pi * 119.9169832 Ohms, where 119.9169832 = 4*10^-7 * 299792458 (exact value). [The 2nd equality is valid only for the SI definition that was in effect until 2019.]

Equals 2*alpha*h/e^2, where alpha is the fine-structure constant, h is the Planck constant and e is the elementary charge. The decimal expansion of Z_0 in SI units after the redefinition in 2019 is 2*A003673*A003676/A081823^2. - Jianing Song, Nov 25 2023

Example

376.730313 ... Ohm [also kg * m^2 * s^-3 * A^-2].

Mathematica

RealDigits[4*Pi*10^-7*299792458, 10, 105] // First (* Jean-François Alcover, Mar 07 2014 *)

Crossrefs

Cf. A003673, A003676, A081823.

Other assigned constants: A003678, A182999, A081799, A019694, A072915, A213611, A213612, A213613, A213614.

Sequence in context: A245259 A075785 A105735 * A296343 A347155 A371240

Adjacent sequences: A213607 A213608 A213609 * A213611 A213612 A213613

Keyword

nonn,cons

Author

Stanislav Sykora, Jun 16 2012

Extensions

Edited by Andrey Zabolotskiy, Aug 12 2020

Status

approved