|
|
A162747
|
|
A factorial-Pascal matrix.
|
|
1
|
|
|
1, 1, 1, 1, 3, 1, 1, 6, 6, 1, 1, 10, 20, 10, 1, 1, 15, 50, 50, 15, 1, 1, 21, 105, 176, 105, 21, 1, 1, 28, 196, 497, 497, 196, 28, 1, 1, 36, 336, 1204, 1830, 1204, 336, 36, 1, 1, 45, 540, 2604, 5634, 5634, 2604, 540, 45, 1, 1, 55, 825, 5160, 15150, 21642, 15150, 5160, 825
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,5
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Number triangle T(n,k)=sum{j=0..n, C(n,j)*C(n-j,2(k-j))*if(j<=k,(k-j)!,0)}.
G.f.: 1/(1-x-xy-x^2*y/(1-x-xy-x^2*y/(1-x-xy-2x^2*y/(1-x-xy-2x^2*y/(1-x-xy-3x^2*y/(1-... (continued fraction). [From Paul Barry, Apr 12 2010]
|
|
EXAMPLE
|
Triangle begins
1,
1, 1,
1, 3, 1,
1, 6, 6, 1,
1, 10, 20, 10, 1,
1, 15, 50, 50, 15, 1,
1, 21, 105, 176, 105, 21, 1,
1, 28, 196, 497, 497, 196, 28, 1,
1, 36, 336, 1204, 1830, 1204, 336, 36, 1,
1, 45, 540, 2604, 5634, 5634, 2604, 540, 45, 1,
1, 55, 825, 5160, 15150, 21642, 15150, 5160, 825, 55, 1
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|