A020805 Decimal expansion of 1/sqrt(48).

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

Offset

0,2

Comments

Or 1/(4 sqrt(3)), which should look familiar to anyone who has studied Ramanujan's approximation for the partition numbers (see Conway and Guy). - Alonso del Arte, May 19 2011

This constant is the ratio of the area (A) to the perimeter (P) of an equilateral triangle with unit side, A/P = 1/(4 sqrt(3)). - José de Jesús Camacho Medina, Feb 09 2018

References

J. H. Conway and R. K. Guy, The Book of Numbers, Copernicus Press, NY, 1996, p. 95.

Links

Ivan Panchenko, Table of n, a(n) for n = 0..1000

Steven Finch, Integer Partitions, September 22, 2004. [Cached copy, with permission of the author]

Example

0.1443375672974...

Mathematica

RealDigits[1/Sqrt[48], 10, 100][[1]] (* Alonso del Arte, May 19 2011 *)

Prog

(PARI) sqrt(1/48)

Crossrefs

Sequence in context: A344894 A305403 A344895 * A200587 A307836 A106147

Adjacent sequences: A020802 A020803 A020804 * A020806 A020807 A020808

Keyword

nonn,cons,easy

Author

N. J. A. Sloane

Status

approved