|
| |
|
|
A166950
|
|
Number of reduced words of length n in Coxeter group on 11 generators S_i with relations (S_i)^2 = (S_i S_j)^13 = I.
|
|
0
| |
|
|
1, 11, 110, 1100, 11000, 110000, 1100000, 11000000, 110000000, 1100000000, 11000000000, 110000000000, 1100000000000, 10999999999945, 109999999998900, 1099999999983555, 10999999999781100, 109999999997266500
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| The initial terms coincide with those of A003953, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
|
|
|
FORMULA
| G.f. (t^13 + 2*t^12 + 2*t^11 + 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 +
2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(45*t^13 - 9*t^12 - 9*t^11 - 9*t^10 -
9*t^9 - 9*t^8 - 9*t^7 - 9*t^6 - 9*t^5 - 9*t^4 - 9*t^3 - 9*t^2 - 9*t + 1)
|
|
|
CROSSREFS
| Sequence in context: A165796 A166369 A166551 * A167112 A167664 A167914
Adjacent sequences: A166947 A166948 A166949 * A166951 A166952 A166953
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| John Cannon (john(AT)maths.usyd.edu.au) and N. J. A. Sloane (njas(AT)research.att.com), Dec 03 2009
|
| |
|
|
