|
| |
|
|
A081994
|
|
Triangle read by rows in which the n-th row contains n numbers not occurring earlier such that every entry is coprime to all the members of the row and column it belongs.
|
|
3
| |
|
|
1, 2, 3, 5, 4, 7, 9, 11, 8, 13, 17, 19, 15, 14, 23, 29, 25, 31, 27, 16, 37, 41, 43, 47, 53, 21, 10, 59, 49, 61, 67, 55, 71, 39, 32, 73, 79, 83, 89, 97, 65, 77, 51, 38, 101, 103, 91, 107, 109, 113, 127, 95, 33, 34, 131, 121, 137, 139, 149, 151, 157, 161, 85, 57, 26, 163, 167
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Observation: The second leading diagonal contains even numbers and all other diagonals mandatorily contain odd numbers. (Proof?)
|
|
|
EXAMPLE
| Triangle begins:
1
2 3
5 4 7
9 11 8 13
17 19 15 14 23
...
|
|
|
CROSSREFS
| Cf. A081995, A081996, A081997.
Sequence in context: A102399 A118318 A084937 * A090252 A140140 A119474
Adjacent sequences: A081991 A081992 A081993 * A081995 A081996 A081997
|
|
|
KEYWORD
| tabl,nonn
|
|
|
AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 05 2003
|
|
|
EXTENSIONS
| Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 29 2003
|
| |
|
|
