|
| |
|
|
A129867
|
|
Row sums of triangular array T: T(j,k) = k*(j-k)! for k < j, T(j,k) = 1 for k = j; 1 <= k <= j.
|
|
5
|
|
|
|
1, 2, 5, 14, 47, 200, 1073, 6986, 53219, 462332, 4500245, 48454958, 571411271, 7321388384, 101249656697, 1502852293010, 23827244817323, 401839065437636, 7182224591785949, 135607710526966262, 2696935204638786575
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
T read by rows is in A130469.
First differences are 1, 3, 9, 33, 153, 873, 5913, ... (see A007489), second differences are 2, 6, 24, 120, 720, 5040, ... (see A000142 ).
First terms of the sequences of m-th differences are 1, 2, 4, 14, 64, ... (see A055790, A047920, A068106).
Antidiagonal sums are 1, 1, 3, 8, 29, 135, ... (see A130470) with first differences 0, 2, 5, 21, 106, ... (see A130471).
Equals the row sums of irregular triangle A182961. [From Paul D. Hanna, Mar 05 2012]
|
|
|
LINKS
|
Vincenzo Librandi, Table of n, a(n) for n = 1..100
|
|
|
EXAMPLE
|
First seven rows of T are
[ 1 ]
[ 1, 1 ]
[ 2, 2, 1 ]
[ 6, 4, 3, 1 ]
[ 24, 12, 6, 4, 1 ]
[ 120, 48, 18, 8, 5, 1 ]
[ 720, 240, 72, 24, 10, 6, 1 ]
|
|
|
PROG
|
(MAGMA) m:=21; [ &+([ k*Factorial(j-k): k in [1..j-1] ] cat [ 1 ]): j in [1..m] ]; /* Klaus Brockhaus, May 28 2007 */
|
|
|
CROSSREFS
|
Cf. A130469, A007489, A000142, A055790, A047920, A068106, A130470, A130471.
Cf. A182961.
Sequence in context: A007268 A109156 A143918 * A119841 A149905 A149906
Adjacent sequences: A129864 A129865 A129866 * A129868 A129869 A129870
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Paul Curtz, May 24 2007
|
|
|
EXTENSIONS
|
Edited and extended by Klaus Brockhaus, May 28 2007
|
|
|
STATUS
|
approved
|
| |
|
|
