A345736 Decimal expansion of the surface area of the catenoid-shaped soap film between two parallel coaxial unit-radius circular rings whose distance between their centers is maximal (2*A033259).

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

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..20000

Markus Deserno, Notes on Differential Geometry, with special emphasis on surfaces in R^3, 2004. See p. 28.

Lev A. Slobozhanin, J. Iwan, D. Alexander and Viral D. Patel, The stability margin for stable weightless liquid bridges, Physics of Fluids, Vol. 14, No. 1 (2002), pp. 209-224. See p. 222.

Eric Weisstein's World of Mathematics, Minimal Surface of Revolution.

Formula

Equals 2*Pi*A085984.

Example

7.53780320580457797882651822069283034551193592152611...

Mathematica

RealDigits[2 * Pi * x /. FindRoot[x == Coth[x], {x, 1}, WorkingPrecision -> 120], 10, 100][[1]]

Crossrefs

Cf. A033259, A085984, A253545.

Sequence in context: A019935 A255646 A255196 * A206643 A257499 A144846

Adjacent sequences: A345733 A345734 A345735 * A345737 A345738 A345739

Keyword

nonn,cons

Author

Amiram Eldar, Jun 25 2021

Status

approved