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Search: id:A081784
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A081784 Continued cotangent for zeta(3). +0
1
1, 10, 122, 33429, 1447509608, 3251816299888840778, 10657606087425320549792856871886476385, 1233698091085791193532165615536619532897409600456434390187369062304735077655 (list; graph; listen)
OFFSET

0,2

FORMULA

zeta(3)=cot(sum(n>=0, n, (-1)^n*acot(a(n))); let b(0)=zeta(3), b(n)=(b(n-1)*floor(b(n-1))+1)/(b(n-1)-floor(b(n-1)) then a(n)=floor(b(n))

PROGRAM

(PARI) ?bn=vector(100); b(n)=if(n<0, 0, bn[n]); bn[1]=zeta(3); ?for(n=2, 10, bn[n]=(b(n-1)*floor(b(n-1))+1)/(b(n-1)-floor(b(n-1)))) ?a(n)=floor(b(n+1))

CROSSREFS

Cf. A001620, A002666, A002667.

Sequence in context: A091692 A098309 A056116 this_sequence A005174 A034668 A123358

Adjacent sequences: A081781 A081782 A081783 this_sequence A081785 A081786 A081787

KEYWORD

nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 10 2003

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Last modified December 17 13:29 EST 2009. Contains 170826 sequences.


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