|
| |
|
|
A143971
|
|
Triangle read by rows, (3n-2) subsequences decrescendo
|
|
1
| |
|
|
1, 4, 1, 7, 4, 1, 10, 7, 4, 1, 13, 10, 7, 4, 1, 16, 3, 10, 7, 4, 1, 19, 16, 13, 10, 7, 4, 1, 22, 19, 16, 13, 10, 7, 4, 1, 25, 2, 19, 16, 13, 10, 7, 4, 1
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Row sums = pentagonal numbers, A000326: (1, 5, 12, 22, 35,...).
|
|
|
FORMULA
| Triangle read by rows, (3n-2) subsequences decrescendo; 1<=k<=n.
(1, 4, 7, 10, 13,...) in every column.
T(n,k) = f(x), (3*x - 2), x = (n-k+1).
|
|
|
EXAMPLE
| First few rows of the triangle =
1;
4, 1;
7, 4, 1;
10, 7, 4, 1;
Example: T(6,2) = 13; (n-k+1) = 5 = x, then (3*x - 2) = 13.
|
|
|
CROSSREFS
| A016777, A000326
Sequence in context: A158860 A037022 A037023 * A016688 A143972 A019651
Adjacent sequences: A143968 A143969 A143970 * A143972 A143973 A143974
|
|
|
KEYWORD
| nonn,tabl
|
|
|
AUTHOR
| Gary W. Adamson (qntmpkt(AT)yahoo.com), Sep 06 2008
|
| |
|
|
