|
| |
|
|
A105868
|
|
Number triangle C(n,k)C(k,n-k).
|
|
3
| |
|
|
1, 0, 1, 0, 2, 1, 0, 0, 6, 1, 0, 0, 6, 12, 1, 0, 0, 0, 30, 20, 1, 0, 0, 0, 20, 90, 30, 1, 0, 0, 0, 0, 140, 210, 42, 1, 0, 0, 0, 0, 70, 560, 420, 56, 1, 0, 0, 0, 0, 0, 630, 1680, 756, 72, 1, 0, 0, 0, 0, 0, 252, 3150, 4200, 1260, 90, 1, 0, 0, 0, 0, 0, 0, 2772, 11550, 9240, 1980, 110, 1, 0, 0
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,5
|
|
|
COMMENTS
| Row sums are the central trinomial coefficients A002426. Diagonal sums are A105869.
Product of A007318 and this sequence is A008459.
Coefficient array for polynomials P(n,x)=x^n*F(1/2-n/2,-n/2;1;4/x). [From Paul Barry (pbarry(AT)wit.ie), Oct 04 2008]
|
|
|
EXAMPLE
| Triangle begins
1;
0,1;
0,2,1;
0,0,6,1;
0,0,6,12,1;
0,0,0,30,20,1;
|
|
|
CROSSREFS
| Cf. A063007, A105870.
Sequence in context: A034093 A057150 A185663 * A057275 A057271 A021480
Adjacent sequences: A105865 A105866 A105867 * A105869 A105870 A105871
|
|
|
KEYWORD
| easy,nonn,tabl
|
|
|
AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Apr 23 2005
|
| |
|
|
