login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A128875 Denominator of the continued fraction convergents of the decimal concatenation of the powers of 2. 0
1, 8, 673, 681, 11569, 12250, 685319, 697569, 1382888, 2080457, 5543802, 13168061, 1546206939, 1559375000, 6224331939, 14008038878, 76264526329, 90272565207, 798445047985, 1687162661177, 66597788833888, 134882740328953 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
The powers of 2 = 1,2,4,8,16,32,64,... are concatenated and then preceded by a decimal point to create the fraction N = .1248163264128... This number is then evaluated with n=0,m=steps to iterate,x = N, a(0)=floor(N) using the loop: do a(n)=floor(x) x=1/(x-a(n)) n=n+1 loop until n=m
PROG
(PARI) g(n) = f="."; for(x=0, n, a=concat(f, 2^x)); f=eval(f) { default(realprecision, 1000); cf = vector(1000); cf = contfrac(f); for(m1=0, m-1, r=cf[m1+1]; forstep(n=m1, 1, -1, r = 1/r; r+=cf[n]; ); numer=numerator(r); denom=denominator(r); print1(denom", "); numer2=numer; denom2=denom; ) }
CROSSREFS
Sequence in context: A172919 A286394 A101180 * A199801 A278857 A334088
KEYWORD
frac,nonn,base
AUTHOR
Cino Hilliard, Apr 18 2007
EXTENSIONS
Edited by Charles R Greathouse IV, Apr 25 2010
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 19 01:34 EDT 2024. Contains 370952 sequences. (Running on oeis4.)