login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A002595 Denominators of Taylor series expansion of arcsin(x). Also arises from arccos(x), arccsc(x), arcsec(x), arcsinh(x).
(Formerly M4233 N1768)
6
1, 6, 40, 112, 1152, 2816, 13312, 10240, 557056, 1245184, 5505024, 12058624, 104857600, 226492416, 973078528, 2080374784, 23622320128, 30064771072, 635655159808, 446676598784, 11269994184704, 23639499997184, 6597069766656 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

arcsin(x) is usually written as x + x^3/(2*3) + 1*3*x^5/(2*4*5) + 1*3*5*x^7/(2*4*6*7) + ..., = x + 1/6*x^3 + 3/40*x^5 + 5/112*x^7 + 35/1152*x^9 + 63/2816*x^11 + ... when reduced to lowest terms.

arccos(x) = Pi/2 - (x + 1/6*x^3 + 3/40*x^5 + 5/112*x^7 + 35/1152*x^9 + 63/2816*x^11 + ...).

arccsc(x) = 1/x+1/(6*x^3)+3/(40*x^5)+5/(112*x^7)+35/(1152*x^9)+63/(2816*x^11)+...

arcsec(x) = Pi/2 -(1/x+1/(6*x^3)+3/(40*x^5)+5/(112*x^7)+35/(1152*x^9)+63/(2816*x^11)+...)

arcsinh(x) = x-1/6*x^3+3/40*x^5-5/112*x^7+35/1152*x^9-63/2816*x^11+...

arccsc(x) = arcsin(1/x) and arcsec(x) = arccos(1/x): 1 < |x|

arcsch(x) = arsinh(1/x) for 1 < |x|

Also denominator of (2n-1)!! / ((2n+1)*(2n)!!) (n=>0).

REFERENCES

W. G. Bickley and J. C. P. Miller, Numerical differentiation near the limits of a difference table, Phil. Mag., 33 (1942), 1-12 (plus tables).

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 88.

H. B. Dwight, Tables of Integrals and Other Mathematical Data, Macmillan, NY, 1968, Chap. 3.

Focus, vol. 16, no. 5, page 32, Oct 1996.

H. E. Salzer, Coefficients for expressing the first twenty-four powers in terms of the Legendre polynomials, Math. Comp., 3 (1948), 16-18.

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

T. D. Noe, Table of n, a(n) for n=0..200

Eric Weisstein's World of Mathematics, Inverse Cosecant

Eric Weisstein's World of Mathematics, Inverse Cosine

Eric Weisstein's World of Mathematics, Inverse Secant

Eric Weisstein's World of Mathematics, Inverse Sine

Eric Weisstein's World of Mathematics, Inverse Hyperbolic Cosecant

Eric Weisstein's World of Mathematics, Inverse Hyperbolic Sine

Eric Weisstein's World of Mathematics, Archimedes' Spiral

FORMULA

Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 06 2009: (Start)

a(n) =denom((2*n)!/(2^(2*n)*(n)!^2*(2*n+1)))

(End)

CROSSREFS

A055786(n) / a(n) = A001147(n) / ( A000165(n) * (2*n+1))

Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 06 2009: (Start)

Cf. A162443 where BG1[ -3,n] = (-1)*A002595(n-1)/A055786(n-1) for n =>1.

(End)

Sequence in context: A200945 A110424 A114079 * A089207 A027777 A073773

Adjacent sequences:  A002592 A002593 A002594 * A002596 A002597 A002598

KEYWORD

nonn,frac,nice,easy

AUTHOR

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 12:30 EST 2012. Contains 206013 sequences.