|
| |
|
|
A045867
|
|
Theta series of quadratic form with Gram matrix [ 4, 1, 2, 1; 1, 4, 1, 0; 2, 1, 6, -2; 1, 0, -2, 20 ].
|
|
3
| |
|
|
1, 0, 4, 6, 2, 6, 2, 6, 10, 2, 8, 14, 24, 10, 14, 10, 26, 14, 38, 14, 32, 18, 14, 16, 40, 20, 24, 34, 40, 12, 60, 24, 34, 18, 36, 30, 50, 2, 40, 30, 60, 34, 70, 30, 64, 64, 52, 42, 72, 42, 60, 50, 72, 34, 62, 38, 80, 54, 72, 36, 100, 52, 56, 76, 90, 52, 126, 36, 80, 72, 100
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
COMMENTS
| This is the 4-dimensional Elkies_C lattice.
|
|
|
REFERENCES
| N. D. Elkies, Elliptic and modular curves..., in AMS/IP Studies in Advanced Math., 7 (1998), 21-76, esp. p. 57.
|
|
|
LINKS
| John Cannon, Table of n, a(n) for n = 0..5000
|
|
|
PROG
| (PARI) {a(n)=if(n<1, n==0, qfrep([ 4, 1, 2, 1; 1, 4, 1, 0; 2, 1, 6, -2; 1, 0, -2, 20 ], n, 1)[n]*2)} /* Michael Somos Apr 02 2006 */
|
|
|
CROSSREFS
| Dual lattice to A045866.
Sequence in context: A160502 A010669 A029677 * A114403 A137662 A153124
Adjacent sequences: A045864 A045865 A045866 * A045868 A045869 A045870
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
EXTENSIONS
| More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jun 22 2000
|
| |
|
|
