A299793 - OEIS

%I #52 Jun 09 2021 22:39:23

%S 3,5,9,5,0,2,0,7,1,4,9,4,7,2,7,0,5,6

%N Decimal expansion of 4*c^2, where c is the speed of light in vacuum in SI units.

%C This constant appears in the denominator of the formula for the vacuum permittivity (epsilon_0) also called permittivity of free space or the electric constant (see below):

%C epsilon_0 = 10^7 / (359502071494727056*Pi) [C^2/(N*m^2)], (see links and A081799).

%C Note that 359502071494727056*Pi is the surface area of a sphere of radius 299792458.

%C Prime factors of this number are 2^4, 7^2, 73^2, 293339^2.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Permittivity">Permittivity</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Vacuum_permittivity">Vacuum permittivity</a>

%F Equals 4*299792458^2 = 2^4*7^2*73^2*293339^2 = 4*A003678^2 = 4*A182999.

%e 4*c^2 = 359502071494727056 [m^2 * s^-2], exact.

%t IntegerDigits[4*299792458^2] (* _Michael De Vlieger_, Feb 22 2018 *)

%Y Cf. A000796, A003678, A081799, A182999.

%K nonn,cons,fini,full

%O 18,1

%A _Omar E. Pol_, Feb 21 2018