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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A014704 Expansion of ((theta_2)^4+(theta_3)^4)/(Delta_24)^2. 0
1, 72, 2400, 52576, 870732, 11739984, 134825216, 1359259200, 12290396058, 101268020984, 769721861376, 5449376818656, 36216000728200, 227395735413552, 1356190070338560, 7717657198319936, 42069113073665703, 220400042813587800 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

REFERENCES

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 105.

PROG

(PARI) {a(n)=local(A); if(n<0, 0, A=x*O(x^n); polcoeff( sum(k=1, n, 24*sumdiv(k, d, d%2*d)*x^k, 1+A)/eta(x+A)^48, n))} /* Michael Somos Feb 15 2006 */

CROSSREFS

Sequence in context: A037251 A008659 A187303 * A035118 A017788 A035731

Adjacent sequences:  A014701 A014702 A014703 * A014705 A014706 A014707

KEYWORD

nonn

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 14 13:08 EST 2012. Contains 205623 sequences.