login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A014013 Alternating Egyptian fraction expansion of Pi-3. 4
7, 790, 749896, 1270073831726, 3264508855407706377676178, 18710490702451568752627532846550947209438603938993 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The next term has 99 digits.

LINKS

Table of n, a(n) for n=1..6.

Index entries for sequences related to Egyptian fractions

FORMULA

Pi  -3 = Sum_{k>=1} (-1)^(k+1)/a(k) = 0.14159...; a(n) = (-1)^(n+1)*u(n) where u(1)=7, u(n) = trunc(1/(Pi - 3 - Sum_{k=1..n-1} 1/u(k))) and trunc(x) = floor(x) if x >= 0, trunc(x) = ceiling(x) if x < 0.

EXAMPLE

1/(Pi - 3 - 1/7 + 1/790) = 749896.4427... hence a(3)=749896.

CROSSREFS

Sequence in context: A020470 A182282 A171245 * A001467 A278438 A279120

Adjacent sequences:  A014010 A014011 A014012 * A014014 A014015 A014016

KEYWORD

nonn,changed

AUTHOR

Simon Plouffe

EXTENSIONS

Title correction by Stanislav Sykora, May 05 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 18 15:13 EDT 2019. Contains 324213 sequences. (Running on oeis4.)