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A073833 Numerators of b(n) where b(1) = 1, b(i) = b(i-1) + 1/b(i-1). 3
1, 2, 5, 29, 941, 969581, 1014556267661, 1099331737522548368039021, 1280590510388959061548230114212510564911731118541, 1726999038066943724857508638586386504281539279376091034086485112150121338989977841573308941492781 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Lim n -> infinity (1/n)*exp(2*(b(n)^2-2n)) = c = 0.57...... - Benoit Cloitre, Oct 16 2002

a(n) is also the numerator of the fractional chromatic number of the Mycielski graph M_n - Eric W. Weisstein, Mar 05 2011

REFERENCES

H. L. Montgomery, Ten Lectures on the Interface Between Analytic Number Theory and Harmonic Analysis, Amer. Math. Soc., 1996, p. 187.

D. J. Newman, A Problem Seminar, Springer; see Problem #60.

J. H. Silverman, The arithmetic of dynamical systems, Springer, 2007, see p. 113 Table 3.1

LINKS

Table of n, a(n) for n=1..10.

Eric Weisstein's World of Mathematics, Fractional Chromatic Number

FORMULA

a(n) = a(n-1)^2 + A073834(n-1)^2; A073834(n) = a(n-1) * A073834(n-1). [From Franklin T. Adams-Watters, Aug 04 2008]

EXAMPLE

1, 2, 5/2, 29/10, 941/290, 969581/272890, 1014556267661/264588959090, 1099331737522548368039021/268440386798659418988490, ...

MATHEMATICA

f[n_]:=n+1/n; Prepend[Numerator[NestList[f, 2, 9]], 1] [From Vladimir Joseph Stephan Orlovsky, 2010Nov19]

Numerator[NestList[# + 1/# &, 1, 10]] [From Eric W. Weisstein, 5 Mar 2001]

PROG

(PARI) {a(n) = local(x, y); if( n<1, 0, if( n<3, n, x = a(n-2)^2; y = a(n-1); y^2 + x * (y - x)))} /* Michael Somos, Mar 05 2012 */

CROSSREFS

See A073834 for denominators.

Sequence in context: A059784 A000283 A121910 * A179554 A086383 A118612

Adjacent sequences:  A073830 A073831 A073832 * A073834 A073835 A073836

KEYWORD

frac,nonn

AUTHOR

Alex Fink (finks(AT)telus.net), Aug 12 2002

STATUS

approved

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Last modified May 22 13:19 EDT 2013. Contains 225548 sequences.