|
| |
|
|
A107862
|
|
Triangle, read by rows, where T(n,k) = C(n*(n-1)/2-k*(k-1)/2+n-k, n-k).
|
|
13
| |
|
|
1, 1, 1, 3, 2, 1, 20, 10, 3, 1, 210, 84, 21, 4, 1, 3003, 1001, 220, 36, 5, 1, 54264, 15504, 3060, 455, 55, 6, 1, 1184040, 296010, 53130, 7315, 816, 78, 7, 1, 30260340, 6724520, 1107568, 142506, 14950, 1330, 105, 8, 1, 886163135, 177232627, 26978328, 3262623
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,4
|
|
|
COMMENTS
| Remarkably, the following matrix products are all equal to A107876: A107862^-1*A107867 = A107867^-1*A107870 = A107870^-1*A107873.
|
|
|
EXAMPLE
| Triangle begins:
1;
1,1;
3,2,1;
20,10,3,1;
210,84,21,4,1;
3003,1001,220,36,5,1;
54264,15504,3060,455,55,6,1;
1184040,296010,53130,7315,816,78,7,1; ...
|
|
|
PROG
| (PARI) T(n, k)=binomial(n*(n-1)/2-k*(k-1)/2+n-k, n-k)
|
|
|
CROSSREFS
| Cf. A014068 (column 0), A107864 (column 1), A107863 (column 2), A107865, A107867, A107870, A107876.
Sequence in context: A129377 A136733 A117269 * A117265 A107727 A087041
Adjacent sequences: A107859 A107860 A107861 * A107863 A107864 A107865
|
|
|
KEYWORD
| nonn,tabl
|
|
|
AUTHOR
| Paul D. Hanna (pauldhanna(AT)juno.com), Jun 04 2005
|
| |
|
|
