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Search: id:A117216
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| A117216 |
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Number of points in the standard root system version of the D_4 lattice having L_infinity norm n. |
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+0
2
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OFFSET
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0,2
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COMMENT
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This lattice consists of all points (w,x,y,z) where w,x,y,z are integers with an even sum.
The L_infinity norm of a vector is the largest component in absolute value.
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REFERENCES
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J. H. Conway and N. J. A. Sloane, Sphere Packings, Lattices and Groups, Springer-Verlag, Chap. 4.
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LINKS
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G. Nebe and N. J. A. Sloane, Home page for this lattice
Index entries for sequences related to D_4 lattice
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CROSSREFS
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Cf. A110907.
Sequence in context: A135848 A089548 A146762 this_sequence A077818 A111176 A072108
Adjacent sequences: A117213 A117214 A117215 this_sequence A117217 A117218 A117219
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KEYWORD
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nonn,easy,more
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Apr 15 2008
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