A164924 Denominators of Egyptian fraction for Pi/4 whose partial sums are the convergents

1, -4, 20, -45, 126, -3066, 98988, -14808876, 1088223045, -11017349070, 121040912274, -2384786370947, 45093873748908, -140317516983756, 553849385827045, -4262743007968170, 28759236845787534, -62522995423971463

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

Links

Table of n, a(n) for n=0..17.

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

Cf. A156618.

Sequence in context: A341895 A163365 A145194 * A033579 A294630 A160799

Adjacent sequences: A164921 A164922 A164923 * A164925 A164926 A164927

Keyword

frac,sign

Author

Jaume Oliver Lafont, Aug 31 2009

Status

approved