|
Search: id:A104571
|
|
|
| A104571 |
|
Triangle formed from the numbers that are 0 or 1 mod 4. |
|
+0
1
|
|
| 1, 4, 1, 5, 4, 1, 8, 5, 4, 1, 9, 8, 5, 4, 1, 12, 9, 8, 5, 4, 1, 13, 12, 9, 8, 5, 4, 1, 16, 13, 12, 9, 8, 5, 4, 1
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
All rows and columns = A042948: 1, 4, 5, 8, 9, 12, 13, 16....(i.e. 0 or 1 mod 4) Row sums = A035608: 1, 5, 10, 18, 27, 39, 52...which relates to sphere packings. A104570 row sums also = A035608.
|
|
FORMULA
|
Columns (with offset) and rows (starting from the right) are congruent to 0 or 1 mod 4: 1, 4, 5, 8, 9, 12, 13...(A042948). The triangle is extracted from the product of lower triangular matrices (with the rest of the terms all zeros): G * R (or R * G); G = [1; 3, 1; 1, 3, 1; 3, 1, 3, 1;...]; R = [1; 1, 1; 1, 1, 1;...].
|
|
EXAMPLE
|
The first few rows are:
1;
4, 1;
5, 4, 1;
8, 5, 4, 1;
9, 8, 5, 4, 1;
...
|
|
CROSSREFS
|
Cf. A042948, A035608, A104570, A104569, A074377.
Sequence in context: A067061 A115210 A030352 this_sequence A105721 A099310 A021880
Adjacent sequences: A104568 A104569 A104570 this_sequence A104572 A104573 A104574
|
|
KEYWORD
|
nonn,uned
|
|
AUTHOR
|
Gary W. Adamson (qntmpkt(AT)yahoo.com), Mar 16 2005
|
|
|
Search completed in 0.002 seconds
|
