OFFSET
1,1
COMMENTS
Equivalently, surface area of a regular icosahedron with unit volume. Among Platonic solids, surface indices decrease with increasing number of faces: A232812 (tetrahedron), 6.0 (cube = hexahedron), A232811 (octahedron), A232810 (dodecahedron), and this one.
An algebraic integer of degree 12 with minimal polynomial x^12 - 41115600x^6 + 765275040000. - Charles R Greathouse IV, Apr 25 2016
LINKS
Stanislav Sykora, Table of n, a(n) for n = 1..1000
Wikipedia, Platonic solid.
EXAMPLE
5.14834855619951564633081294611601906410086411638672414845...
MATHEMATICA
RealDigits[5*Sqrt[3]/(5*(3+Sqrt[5])/12)^(2/3), 10, 120][[1]] (* Amiram Eldar, May 25 2023 *)
PROG
(PARI) 5*sqrt(3)/(5*(3+sqrt(5))/12)^(2/3) \\ Charles R Greathouse IV, Apr 25 2016
CROSSREFS
KEYWORD
AUTHOR
Stanislav Sykora, Dec 01 2013
STATUS
approved