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A128839 Numerators of the continued fraction convergents of the decimal concatenation of the odd natural numbers. 0
1, 2, 3, 8, 11, 140, 151, 442, 1477, 1919, 11072, 12991, 24063, 37054, 98171, 429738, 957647, 6175620, 13308887 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

The 19th convergent breaks down at number 95 so a 16 digit ratio gives 91 digits accuracy!

FORMULA

The odd natural numbers 1,3,5.. are concatenated and then preceded by a decimal point to create the fraction N = .1357911131517... . This number is then evaluated with n=1,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

EXAMPLE

The 19th convergent 13308887/98010000 =

0.13579111315171921232527293133353739414345474951535557596163656769717375777981\

8385878991939598000...

PROG

(PARI) catodd(n) = f="."; forstep(x=1, n, 2, a=concat(f, Str(x))); f=eval(f) cfrac2(m, f) = { default(realprecision, 1000); cf = vector(m+10); cf = contfrac(f); for(m1=1, m-1, r=cf[m1+1]; forstep(n=m1, 1, -1, r = 1/r; r+=cf[n]; ); numer=numerator(r); denom=denominator(r); print1(numer", "); ) }

CROSSREFS

Sequence in context: A139447 A042783 A042583 * A192113 A164817 A002958

Adjacent sequences:  A128836 A128837 A128838 * A128840 A128841 A128842

KEYWORD

frac,nonn,base

AUTHOR

Cino Hilliard (hillcino368(AT)hotmail.com), Apr 16 2007

EXTENSIONS

Edited by Charles R Greathouse IV (charles.greathouse(AT)case.edu), Apr 25 2010

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Last modified February 17 03:45 EST 2012. Contains 205978 sequences.