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A097690 Numerators of the continued fraction n-1/(n-1/...) [n times]. 3
1, 3, 21, 209, 2640, 40391, 726103, 15003009, 350382231, 9127651499, 262424759520, 8254109243953, 281944946167261, 10393834843080975, 411313439034311505, 17391182043967249409, 782469083251377707328 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

The n-th term of the Lucas sequence U(n,1). The denominator is the (n-1)-th term. Adjacent terms of the sequence U(n,1) are relatively prime.

LINKS

Eric Weisstein's World of Mathematics, Lucas Sequence

EXAMPLE

a(4)=209 because 4-1/(4-1/(4-1/4))=209/56

MATHEMATICA

Table[s=n; Do[s=n-1/s, {n-1}]; Numerator[s], {n, 20}]

PROG

sage: [lucas_number1(n, n-1, 1) for n in range(19)] - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 25 2008

CROSSREFS

Cf. A084844, A084845, A097691 (denominators).

Sequence in context: A192314 A136223 A114469 * A037967 A123691 A087918

Adjacent sequences:  A097687 A097688 A097689 * A097691 A097692 A097693

KEYWORD

easy,frac,nonn

AUTHOR

T. D. Noe (noe(AT)sspectra.com), Aug 19 2004

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Last modified February 13 16:54 EST 2012. Contains 205523 sequences.