|
| |
|
|
A111805
|
|
Number triangle T(n,k)=binomial(2(n+k),4k).
|
|
0
| |
|
|
1, 1, 1, 1, 15, 1, 1, 70, 45, 1, 1, 210, 495, 91, 1, 1, 495, 3003, 1820, 153, 1, 1, 1001, 12870, 18564, 4845, 231, 1, 1, 1820, 43758, 125970, 74613, 10626, 325, 1, 1, 3060, 125970, 646646, 735471, 230230, 20475, 435, 1, 1, 4845, 319770, 2704156, 5311735
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,5
|
|
|
COMMENTS
| Related to matchings of the complete graph K_2n: T(n,k)=A100861(2(n+k),2k)/f(2k), where f(n)=(2n-1)!! Column k gives number of standard tableaux of shape (2n+1,1^(4k)).
|
|
|
FORMULA
| Column k has g.f. x^k*sum{j=0..2k+1, binomial(4k+1, 2j)x^j}/(1-x)^(4k+1)
|
|
|
EXAMPLE
| Rows begin
1;
1,1;
1,15,1;
1,70,45,1;
1,210,495,91,1;
|
|
|
CROSSREFS
| Sequence in context: A070644 A174389 A176286 * A176226 A155493 A156939
Adjacent sequences: A111802 A111803 A111804 * A111806 A111807 A111808
|
|
|
KEYWORD
| easy,nonn,tabl
|
|
|
AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Aug 17 2005
|
| |
|
|
