|
Search: id:A119835
|
|
|
| A119835 |
|
Primes p such that 2*p#-1 and 2*p#+1 are twin primes. |
|
+0
3
|
| |
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
2*2-1=3 2*2+1=5, 3 and 5 twin primes so a(1)=2
2*2*3-1=11 2*2*3+1=13, 11 and 13 twin primes so a(2)=3
2*2*3*5-1=59 2*2*3*5+1=61, 59 and 61 twin primes so a(3)=5
|
|
MAPLE
|
isA001359 := proc(n) RETURN(isprime(n) and isprime(n+2)); end: primo := 2 : print(primo); for n from 2 to 20000 do p := ithprime(n); primo := primo*p; if isA001359(2*primo-1) then print(p); fi; od : - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 09 2006
|
|
CROSSREFS
|
Cf. A119833 A119834.
Sequence in context: A006341 A086107 A046713 this_sequence A076609 A117059 A117058
Adjacent sequences: A119832 A119833 A119834 this_sequence A119836 A119837 A119838
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
Pierre CAMI (pierrecami(AT)tele2.fr), May 25 2006
|
|
|
Search completed in 0.002 seconds
|
