|
| |
|
|
A159923
|
|
Rectangular array read by antidiagonals: a(m,n) = greatest non-composite (1 or prime) that divides both m and n.
|
|
1
| |
|
|
1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 3, 1, 1, 1, 2, 1, 2, 5, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 2, 1, 3, 1, 2, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 7, 2, 1, 2, 1, 2, 1, 1, 1, 3, 1, 5, 3, 1, 1, 3, 5, 1, 3, 1, 1
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,5
|
|
|
COMMENTS
| The array is symmetric along the diagonal; so there is a triangular version with the same amount of information which reads the array along rows up to the diagonal: 1,1,2,1,1,3,1,2,1,2,1,1,1,1,5,1,... [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 29 2009]
|
|
|
MAPLE
| A159923 := proc(n, m) local g; for g from max(n, m) to 2 by -1 do if isprime(g) and (n mod g) = 0 and (m mod g) = 0 then RETURN(g) ; fi; od: RETURN(1) ; end: for d from 2 to 22 do for m from 1 to d-1 do n := d-m ; printf("%d, ", A159923(n, m)) ; od: od: [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 29 2009]
|
|
|
CROSSREFS
| Sequence in context: A053632 A124060 A140194 * A003989 A091255 A175466
Adjacent sequences: A159920 A159921 A159922 * A159924 A159925 A159926
|
|
|
KEYWORD
| nonn,tabl
|
|
|
AUTHOR
| Leroy Quet, Apr 26 2009
|
|
|
EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 29 2009
|
| |
|
|
