OFFSET
1,1
COMMENTS
The general expression is a lower bound (due to H. Minkowski) on the discriminant of a number field of degree N.
The corresponding value for N = 2 matches A091476.
REFERENCES
B. Mazur, Algebraic Numbers, in The Princeton Companion to Mathematics, Editor T. Gowers, Princeton University Press, 2008, Section IV.1, page 330.
LINKS
Stanislav Sykora, Table of n, a(n) for n = 1..2000
FORMULA
Equals 81*Pi^3/256.
EXAMPLE
9.8105797308761149773968028142000508257040952102995848563504202594...
MATHEMATICA
n = 3; First@ RealDigits[N[(Pi/4)^n (n^n/n!)^2, 120]] (* Michael De Vlieger, Nov 19 2015 *)
PROG
(PARI) N=3; (Pi/4)^N*(N^N/N!)^2
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Stanislav Sykora, Nov 19 2015
STATUS
approved