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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A060506 Numerators of the asymptotic expansion of the Airy function Ai(x). 2
1, 5, 385, 425425, 1301375075, 188699385875, 2252127170418125, 6344885703973691875, 64115070038654156396875, 2830616227136542350765634375, 34904328696820703727291037478125, 88069967543659875631905704109578125 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

The series arises in the asymptotic expansion of the Airy function A(x) for large |x| as Ai(x)~pi^(-1/2)/2*x^(-1/4)*exp(-z)*sum((-1)^k*c(k)*z^(-k),k=0..infinity), where z=2/3*x^(3/2). a(k) is the numerator of the fully canceled c(k).

REFERENCES

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings).

LINKS

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

NIST's Digital Library of Mathematical Functions, Airy and Related Functions (Poincare-Type Expansions) by Frank W. J. Olver.

FORMULA

a(k)=numer(product((2*l+1), l=k..3*k-1)/216^k/k!)

EXAMPLE

a(2)=385 because for k=2, product((2*l+1),l=k..3*k-1)/216^k/k! = 385/3456 and we take the numerator of the fully canceled fraction.

MATHEMATICA

a[ n_] := Numerator[Product[k, {k, 1, 6 n - 1, 2}]  /n! / 216^n] (* Michael Somos, Oct 14 2011 *)

CROSSREFS

Cf. A060507.

Sequence in context: A198902 A100474 A152438 * A057633 A193126 A006700

Adjacent sequences:  A060503 A060504 A060505 * A060507 A060508 A060509

KEYWORD

easy,frac,nonn

AUTHOR

Michael Praehofer (praehofer(AT)ma.tum.de), Mar 22 2001

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 14 13:08 EST 2012. Contains 205623 sequences.