

A232813


Decimal expansion of the minimum surface index of a closed cylinder.


5



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

1,1


COMMENTS

Equivalently, the minimum surface area among all closed cylinders (cans) enclosing a unit volume. It is attained when the cylinder is right circular and its height matches the diameter of its base. For evident reasons, this value should be called the 'cannery constant'. Its determination is a nice exercise in elementary analysis.
For a general definition of surface index, see A232808.


LINKS

Stanislav Sykora, Table of n, a(n) for n = 1..1000
Wikipedia, Cylinder (geometry)


FORMULA

(54*Pi)^(1/3) = 3*(2*Pi)^(1/3).


EXAMPLE

5.53581044593208525729041163876696408034010879864785498817652692...


CROSSREFS

Cf. Other surface indices: A232808 (spheres), A232809, A232810, A232811, A232812 (platonic solids), A232814 (open cylinders), A232815 (closed cones), A232816 (open cones), A232817 (open tubes).
Sequence in context: A089486 A199617 A195693 * A267033 A278928 A273826
Adjacent sequences: A232810 A232811 A232812 * A232814 A232815 A232816


KEYWORD

nonn,cons,easy


AUTHOR

Stanislav Sykora, Dec 03 2013


STATUS

approved



