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A128844 Numerators of the continued fraction convergents of the decimal concatenation of the lower bound of twin primes. 0
0, 1, 1, 6, 7, 13, 33, 46, 79, 204, 283, 487, 770, 1257, 3284, 4541, 7825, 12366, 20191, 517141, 537332, 17711765, 35960862, 89633489, 10702346053, 53601363754, 439513256085, 493114619839, 932627875924, 2358370371687, 3290998247611 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..30.

FORMULA

The lower bounds of twin primes 3,5,11,17... are concatenated and then preceded by a decimal point to create the fraction N = .35111729... . 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) cattwinsL(n) = a="."; forprime(x=3, n, if(ispseudoprime(x+2), a=concat(a, Str(x)))); a=eval(a) 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: A042723 A160825 A020689 * A128850 A042025 A041072

Adjacent sequences:  A128841 A128842 A128843 * A128845 A128846 A128847

KEYWORD

frac,nonn,base

AUTHOR

Cino Hilliard, Apr 16 2007

EXTENSIONS

Edited by Charles R Greathouse IV, Apr 25 2010

STATUS

approved

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Last modified June 4 00:49 EDT 2020. Contains 334808 sequences. (Running on oeis4.)