A394804 Decimal expansion of (4*log(2)-1)/(6*log(2)^2).

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

Offset

0,1

Comments

The dimensionless coefficient in the expression for the repulsive electrostatic force between two identical charged conducting spheres in contact. If the charge of each sphere is Q and its radius is R, then the force equals c * k * Q^2/(2*R)^2, where k is the Coulomb constant (A182999) and c is this constant. This formula was first published by Lord Kelvin in 1853.

Links

Table of n, a(n) for n=0..104.

Shubho Banerjee, Mason Levy, McKenna Davis, and Blake Wilkerson, Exact and approximate capacitance and force expressions for the electrostatic interaction between two equal-sized charged conducting spheres, IEEE Transactions on Industry Applications, Vol. 53, No. 3 (2017), pp. 2455-2460; ResearchGate link. See p. 2459.

Aditya S. Khair, Electrostatic forces on two almost touching nonspherical charged conductors, Journal of Applied Physics, Vol. 114, No. 13 (2013), Article 134906. See eq. (1).

Francesco Lacava, Classical Electrodynamics: From Image Charges to the Photon Mass and Magnetic Monopoles, 2nd ed., Springer Cham, 2022. See pp. 89, 94-96.

John Lekner, Electrostatics of two charged conducting spheres, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 468, No. 2145 (2012), 2829-2848; ResearchGate link. See eq. (1.1), p. 2829.

John Lekner, Nurturing genius: the childhood and youth of Kelvin and Maxwell, New Zealand Science Review, Vol. 69, No. 1 (2012), pp. 8-14.

John Lekner, Regions of attraction between like-charged conducting spheres, American Journal of Physics, Vol. 84, No. 6 (2016), pp. 474-477. See eq. (20), p. 476.

John Lekner, Electrostatics of Conducting Cylinders and Spheres, AIP Publishing LLC, 2021. See section 4.6, pp. 4-11 - 4-15.

Francesco Maccarrone and Giampiero Paffuti, Some comments on the electrostatic forces between circular electrodes, Journal of Electrostatics, Vol. 84 (2016), pp. 135-142. See eq. (1), p. 135.

William Thomson (Lord Kelvin), On the mutual attraction or repulsion between two electrified spherical conductors, The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, Series 4, Vol. 5, No. 32 (1853), pp. 287-297. Also published in: William Thomson, Reprint of papers on electrostatics and magnetism, London: Macmillan & Co., 1884, pp. 86-97.

Index entries for transcendental numbers.

Example

0.614901863758374305261686186712096187440422776827643...

Mathematica

RealDigits[(4*Log[2]-1)/(6*Log[2]^2), 10, 120][[1]]

Prog

(PARI) (4*log(2)-1)/(6*log(2)^2)

Crossrefs

Cf. A002162, A182999.

Sequence in context: A068226 A011237 A195433 * A358559 A367563 A016534

Adjacent sequences: A394801 A394802 A394803 * A394805 A394806 A394807

Keyword

nonn,cons

Author

Amiram Eldar, Apr 30 2026

Status

approved