|
Search: id:A111805
|
|
|
| A111805 |
|
Number triangle T(n,k)=binomial(2(n+k),4k). |
|
+0
1
|
|
| 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; listen)
|
|
|
OFFSET
|
0,5
|
|
|
COMMENT
|
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: A040226 A040225 A070644 this_sequence A155493 A156939 A022178
Adjacent sequences: A111802 A111803 A111804 this_sequence A111806 A111807 A111808
|
|
KEYWORD
|
easy,nonn,tabl
|
|
AUTHOR
|
Paul Barry (pbarry(AT)wit.ie), Aug 17 2005
|
|
|
Search completed in 0.002 seconds
|
