|
Search: id:A130194
|
|
|
| A130194 |
|
Let M = lower triangular matrix with 1's on and below the main diagonal, with columns multiplied by +1, +1, -1, -1, repeated; form M^2; read across rows of resulting triangle. |
|
+0
2
|
|
| 1, 2, 1, -1, 2, 1, -4, -1, 2, 1, 1, -4, -1, 2, 1, 6, 1, -4, -1, 2, 1, -1, 6, 1, -4, -1, 2, 1, -8, -1, 6, 1, -4, -1, 2, 1, 1, -8, -1, 6, 1, -4, -1, 2, 1, 10, 1, -8, -1, 6, 1, -4, -1, 2, 1
(list; table; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
A000012(signed)^2.
Left border = A009531: (1, 2, -1, -4, 1, 6, -1,...). Row sums = A130195: (1, 3, 2, -2, -1, 5, 4,...). Row sums of the unsigned triangle = A058074: (1, 3, 4, 8, 9, 15,...).
A009531 in every column: (1, 2, -1, -4, 1, 6, -1,...).
|
|
EXAMPLE
|
First few rows of the triangle are:
1;
2, 1;
-1, 2, 1;
-4, -1, 2, 1;
1, -4, -1, 2, 1;
6, 1, -4, -1, 2, 1;
...
|
|
CROSSREFS
|
Cf. A000012, A058074, A009531.
Sequence in context: A102190 A138650 A137843 this_sequence A113926 A165585 A082506
Adjacent sequences: A130191 A130192 A130193 this_sequence A130195 A130196 A130197
|
|
KEYWORD
|
tabl,sign
|
|
AUTHOR
|
Gary W. Adamson (qntmpkt(AT)yahoo.com), May 16 2007
|
|
|
Search completed in 0.002 seconds
|
