|
Search: id:A140775
|
|
|
| A140775 |
|
A number n is included if p + n/p is prime for every prime p that divides n. |
|
+0
3
|
|
| 2, 6, 10, 22, 30, 34, 42, 58, 70, 78, 82, 102, 118, 130, 142, 190, 202, 210, 214, 274, 298, 310, 322, 330, 358, 382, 394, 442, 454, 462, 478, 510, 538, 562, 582, 610, 622, 658, 694, 714, 730, 742, 790, 838, 862, 922, 930, 970, 1002, 1038, 1042, 1110, 1138, 1198
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
All terms of this sequence are even and squarefree.
|
|
LINKS
|
Leroy Quet, Home Page (listed in lieu of email address)
|
|
EXAMPLE
|
The primes dividing 70 are 2, 5, 7. Now, 2 + 70/2 = 37; 5 + 70/5 = 19; 7 + 70/7 = 17. Since 37, 19 and 17 are each prime, then 70 is included in this sequence.
|
|
MATHEMATICA
|
fQ[n_] := Block[{p = First@ Transpose@ FactorInteger@ n}, Union@ PrimeQ[p + n/p] == {True}]; Select[ Range[2, 1221], fQ@# &] - Robert G. Wilson v, (rgwv(AT)rgwv.com), May 30 2008
|
|
CROSSREFS
|
Cf. A140776, A140777.
Sequence in context: A103628 A034450 A112861 this_sequence A077064 A080715 A034168
Adjacent sequences: A140772 A140773 A140774 this_sequence A140776 A140777 A140778
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Leroy Quet May 29 2008
|
|
EXTENSIONS
|
More terms from Robert G. Wilson v, (rgwv(AT)rgwv.com), May 30 2008
|
|
|
Search completed in 0.002 seconds
|
