|
| |
|
|
A099114
|
|
Number of rhombus tilings of a hexagon with side lengths 2n,2n+2,2n,2n,2n+2,2n which contain the rhombus above and next to the center of the hexagon.
|
|
0
| |
|
|
19, 2252052, 125575149020464, 3624877924928635307525440, 55204136490632334691332479792745796875, 446207680704793917097310140821019734826847707500000000
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
LINKS
| M. Fulmek and C. Krattenthaler, [math/9909038] The number of rhombus tilings of a symmetric hexagon which contain a fixed rhombus on the symmetry axis, II
|
|
|
PROG
| (PARI) a(n)=(1/3-(10*n+2)/(6*n+3)*binomial(2*n, n)^3/binomial(6*n+2, 3*n+1))*prod(i=1, 2*n, prod(j=1, 2*n+2, prod(k=1, 2*n, (i+j+k-1)/(i+j+k-2))))
|
|
|
CROSSREFS
| Cf. A099112-A099117, A008793.
Sequence in context: A177818 A172824 A070632 * A013810 A172875 A172839
Adjacent sequences: A099111 A099112 A099113 * A099115 A099116 A099117
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Ralf Stephan, Oct 01 2004
|
| |
|
|
