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A003715 E.g.f. sin(sin(sin(x))) (odd powers only).
(Formerly M3134)
0
1, -3, 33, -731, 25857, -1311379, 89060065, -7778778091, 849264442881, -113234181108643, 18073465545032353, -3395124358886313595, 740061366713642835201, -185005977382236600650035 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

FORMULA

a(k):=sum(j=0..k, (sum(m=j..k, (2^(-2*j-2*m)*(sum(i=0..(2*j+1)/2, (2*i-2*j-1)^(2*m+1)*(-1)^(i)*binomial(2*j+1,i)))*sum(i=0..(2*m+1)/2, (2*i-2*m-1)^(2*k+1)*binomial(2*m+1,i)*(-1)^(k-i)))/(2*m+1)!))/(2*j+1)!); [From Vladimir Kruchinin, Jun 10 2011]

PROG

(Maxima)

a(k):=sum((sum((2^(-2*j-2*m)*(sum((2*i-2*j-1)^(2*m+1)*(-1)^(i)*binomial(2*j+1, i), i, 0, (2*j+1)/2))*sum((2*i-2*m-1)^(2*k+1)*binomial(2*m+1, i)*(-1)^(k-i), i, 0, (2*m+1)/2))/(2*m+1)!, m, j, k))/(2*j+1)!, j, 0, k); [From Vladimir Kruchinin, Jun 10 2011]

CROSSREFS

Sequence in context: A002916 A009659 A144756 * A009690 A174488 A124432

Adjacent sequences:  A003712 A003713 A003714 * A003716 A003717 A003718

KEYWORD

sign

AUTHOR

R. H. Hardin (rhhardin(AT)att.net), Simon Plouffe (simon.plouffe(AT)gmail.com)

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Last modified February 16 10:53 EST 2012. Contains 205904 sequences.