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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A038534 Numerators of coefficients of EllipticK/Pi. 5
1, 1, 9, 25, 1225, 3969, 53361, 184041, 41409225, 147744025, 2133423721, 7775536041, 457028729521, 1690195005625, 25145962430625, 93990019574025, 90324408810638025, 340357374376418025, 5147380044581630625, 19520119892056100625 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Also, numerators in expansion of hypergeometric series 2F1(1/2,1/2; 1; x).

REFERENCES

B. C. Berndt, Ramanujan's Notebooks Part III, Springer-Verlag, see p. 91, Eq. 2.1.

FORMULA

a(n) = 2^(-2 w[n])Binomial[2n, n]^2 with w[n]=A000120 = number of 1's in binary expansion of n

MATHEMATICA

Numerator@ CoefficientList[ Series[ EllipticK@x, {x, 0, 19}]/Pi, x] (* Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 19 2007 *)

CROSSREFS

Equals A001790(n)^2.

Cf. A038533, A038535.

Sequence in context: A193065 A201807 A048056 * A117755 A144114 A144701

Adjacent sequences:  A038531 A038532 A038533 * A038535 A038536 A038537

KEYWORD

frac,nonn

AUTHOR

Wouter Meeussen (wouter.meeussen(AT)pandora.be), revised Jan 03 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 16 19:06 EST 2012. Contains 205945 sequences.