|
| |
|
|
A111109
|
|
G.f.: -x*(x^6+3*x^5+2*x^4-2*x^3-4*x^2+4*x-1)/((1-x)^2*(1-2*x-x^2)^2).
|
|
0
| |
|
|
0, 1, 2, 5, 14, 40, 111, 301, 803, 2118, 5540, 14397, 37216, 95772, 245505, 627189, 1597413, 4057450, 10280678, 25990933, 65575122, 165138416, 415158963, 1042067549, 2611823431, 6537384302, 16342461128, 40805714573, 101776575332, 253587643300, 631232103045
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
REFERENCES
| M. H. Albert and M. D. Atkinson, Simple permutations and pattern restricted permutations, Discr. Math., 300 (2005), 1-15.
|
|
|
MATHEMATICA
| CoefficientList[ Series[ -x*(x^6 + 3*x^5 + 2*x^4 - 2*x^3 - 4*x^2 + 4*x - 1)/((1 - x)^2*(1 - 2*x - x^2)^2), {x, 0, 30}], x] (from Robert G. Wilson v (rgwv(at)rgwv.com), Oct 15 2005)
|
|
|
CROSSREFS
| Sequence in context: A148319 A126219 A111110 * A081908 A059505 A117189
Adjacent sequences: A111106 A111107 A111108 * A111110 A111111 A111112
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Oct 14 2005
|
|
|
EXTENSIONS
| The published g.f. sgould be multiplied by -1.
|
| |
|
|
