OFFSET
0,1
COMMENTS
The formula for Pi in the formula section was discovered by the mathematician and astronomer Nilakantha Somayaji (1444-1544) (Roy, 1990). - Amiram Eldar, Jan 18 2023
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..10000
Ranjan Roy, The Discovery of the Series Formula for Pi, Mathematics Magazine, Vol. 63, No. 5 (1990), pp. 291-306.
FORMULA
Pi = 16 * Sum_{n>=0} (-1)^n/a(n).
MATHEMATICA
a[n_] := (2*n + 1)*((2*n + 1)^4 + 4); Array[a, 30, 0] (* Amiram Eldar, Jul 16 2022 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Apr 05 2002
STATUS
approved