|
| |
|
|
A140751
|
|
Triangle read by rows, X^n * [1,0,0,0,...] where X = an infinite tridiagonal matrix with (1,0,1,0,1,...) in the main and subdiagonals and (1,1,1,...) in the subsubdiagonal.
|
|
1
| |
|
|
1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 3, 3, 3, 3, 1, 1, 1, 4, 4, 6, 6, 4, 4, 1, 1, 1, 5, 5, 10, 10, 10, 10, 5, 5, 1, 1, 1, 6, 6, 15, 15, 20, 20, 15, 15, 6, 6, 1, 1, 1, 7, 7, 21, 21, 35, 35, 35, 35, 21, 21, 7, 7, 1
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,7
|
|
|
COMMENTS
| Row sums = (2^n - 1): (1, 3, 7, 15, 31,...).
|
|
|
EXAMPLE
| First few rows of the triangle are;
1;
1, 1, 1;
1, 1, 2, 2, 1;
1, 1, 3, 3, 3, 3, 1;
1, 1, 4, 4, 6, 6, 4, 4, 1;
1, 1, 5, 5, 10, 10, 10, 10, 5, 5, 1;
1, 1, 6, 6, 15, 15, 20, 20, 15, 15, 6, 6, 1;
1, 1, 7, 7, 21, 21, 35, 35, 35, 35, 21, 21, 7, 7, 1;
...
|
|
|
CROSSREFS
| Cf. A140750.
Sequence in context: A123682 A134513 A201881 * A162741 A104320 A180264
Adjacent sequences: A140748 A140749 A140750 * A140752 A140753 A140754
|
|
|
KEYWORD
| nonn,tabl
|
|
|
AUTHOR
| Gary W. Adamson & Roger L. Bagula (qntmpkt(AT)yahoo.com), May 26 2008
|
| |
|
|
