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

Author

Jaume Oliver Lafont, Aug 31 2009

Keywords

• frac
• sign

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

Crossrefs

Cf. A156618.

Programs

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; )