[seqfan] Re: computation for D4 lattice (A117216)

franktaw at netscape.net franktaw at netscape.net
Thu Feb 4 12:20:57 CET 2010


By hand computation, I also get A117216(2) = 272.  Specifically:

2,2,2,2 16
2,2,2,0 32
2,2,1,1 96
2,2,0,0 24
2,1,1,0 96
2,0,0,0   8
              -----
              272

Franklin T. Adams-Watters

-----Original Message-----
From: Joerg Arndt <arndt at jjj.de>


* Richard Mathar <mathar at strw.leidenuniv.nl> [Feb 04. 2010 10:24]:
> [...]

Number of points in the standard root system
 version of the D_4 lattice having L_infinity norm n.
http://oeis.org/classic/A117216

...

vc  \\ gives
\\ [1, 40, 272, 888, 2080, 4040, 6960]
\\  0,  1,  2,   3,    4,    5,    6

... in disagreement for n==2
Someone please check.




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