OFFSET
0,2
COMMENTS
1-1/4+1/20-1/45+1/126 = (22/7)/4
1-1/4+1/20-1/45+1/126-1/3066+1/98988 = (355/113)/4
PROG
(PARI) c0=0; for (k=2, 30, m=contfracpnqn(contfrac(Pi/4, k)); c1=m[1, 1]/m[2, 1]; print1(1/(c1-c0), ", "); c0=c1; )
CROSSREFS
KEYWORD
frac,sign
AUTHOR
Jaume Oliver Lafont, Aug 31 2009
STATUS
approved