|
|
A163055
|
|
Number of reduced words of length n in Coxeter group on 12 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I.
|
|
0
|
|
|
1, 12, 132, 1452, 15906, 174240, 1908720, 20908800, 229042770, 2509019700, 27484733100, 301077971700, 3298119892650, 36128829891000, 395768617233000, 4335396381723000, 47491541694374250, 520239981289297500
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
COMMENTS
|
The initial terms coincide with those of A003954, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(55*t^4 - 10*t^3 - 10*t^2 - 10*t + 1)
|
|
MATHEMATICA
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|