|
Search: id:A091417
|
|
|
| A091417 |
|
Integers n which are not the difference of 2 integers A and B where A is less than or equal to n such that AB+1 and AB-1 are both primes. In other words, the product A*B cannot be the middle integer of a twin prime pair. |
|
+0
2
|
|
| 8, 9, 10, 15, 18, 20, 30, 40, 51, 58, 60, 65, 75, 96, 100, 110, 120, 170, 195, 240, 250, 260, 315, 330, 345, 390, 540, 630, 750, 780, 910, 1020, 1720, 1890
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Sequence may be finite. Next term after 1890 if it exists must be greater than 867750.
|
|
EXAMPLE
|
8 is a member: 8 is the difference between these pairs of integers: (9-1) (10-2) (11-3) (12-4) (13-5) (14-6) (15-7) (16-8). Their products (9*1) (10*2), etc. plus and minus 1 are not primes and therefore the products cannot be the middle integers of twin prime sets.
|
|
CROSSREFS
|
Cf. A090695, A091182, A091183. A091418.
Sequence in context: A067683 A072381 A046415 this_sequence A069237 A070480 A135043
Adjacent sequences: A091414 A091415 A091416 this_sequence A091418 A091419 A091420
|
|
KEYWORD
|
nonn,fini
|
|
AUTHOR
|
William F. Sindelar (w_sindelar(AT)juno.com), Jan 05 2004
|
|
|
Search completed in 0.002 seconds
|
