|
Search: id:A119828
|
|
|
| A119828 |
|
Number triangle T(n,k)=(2n)!/(2k)!. |
|
+0
4
|
|
| 1, 2, 1, 24, 12, 1, 720, 360, 30, 1, 40320, 20160, 1680, 56, 1, 3628800, 1814400, 151200, 5040, 90, 1, 479001600, 239500800, 19958400, 665280, 11880, 132, 1, 87178291200, 43589145600, 3632428800, 121080960, 2162160, 24024, 182, 1
(list; table; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
Row sums are A051396(n+1). Diagonal sums are A119829. Inverse is the bi-diagonal array A119830. E.g.f. cosh(x*y)/(1-y*x^2) produces an aerated version.
|
|
FORMULA
|
Number triangle T(n,k)=[k<=n](2n)!/(2k)!
|
|
EXAMPLE
|
Triangle begins
1,
2, 1,
24, 12, 1,
720, 360, 30, 1,
40320, 20160, 1680, 56, 1,
3628800, 1814400, 151200, 5040, 90, 1
|
|
CROSSREFS
|
Sequence in context: A062763 A037943 A073876 this_sequence A101179 A013313 A013317
Adjacent sequences: A119825 A119826 A119827 this_sequence A119829 A119830 A119831
|
|
KEYWORD
|
easy,nonn,tabl
|
|
AUTHOR
|
Paul Barry (pbarry(AT)wit.ie), May 25 2006
|
|
|
Search completed in 0.002 seconds
|
