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A000318 Generalized tangent numbers.
(Formerly M3713 N1517)
0
4, 128, 16384, 4456448, 2080374784, 1483911200768, 1501108249821184, 2044143848640217088, 3605459138582973251584, 7995891855149741436305408, 21776918737280678860353961984, 71454103701490016776039304265728 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

REFERENCES

D. Shanks, Generalized Euler and class numbers, Math. Comp. 21 (1967), 689-694; 22 (1968), 699.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

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

LINKS

Thomas Baruchel, Home Page

FORMULA

The g.f. has the following continued fraction expansion: g.f. = [4, b(0), c(0), b(1), c(1), b(2), c(2), ...] where b(n) = sum(k=0, n, 1/(2*k+1))^2 / (128*(n+1)*x), c(n) = -4/( sum(k=0, n, 1/(2*k+1))*sum(k=0, n+1, 1/(2*k+1))*(2*n+3) ) and each convergent of this continued fraction is a Pad'e approximant of the McLaurin series sum(k=1, \infty, a(n)*x^(n-1)). - Thomas Baruchel, Oct 19 2005

CROSSREFS

Equals 2^(4n-2) * A000182(n).

Sequence in context: A128790 A013823 A130318 * A141367 A141368 A146555

Adjacent sequences:  A000315 A000316 A000317 * A000319 A000320 A000321

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jun 03 2000

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Last modified February 16 03:44 EST 2012. Contains 205860 sequences.