|
| |
|
|
A057706
|
|
Smaller of twin primes whose average is a primorial number.
|
|
4
|
| |
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
According to Caldwell, the next term, if it exists, has more than 100000 digits. - T. D. Noe, May 08 2012
|
|
|
LINKS
|
Table of n, a(n) for n=1..3.
Chris K. Caldwell, Primorial prime
|
|
|
EXAMPLE
|
(5+7)/2 = 6 = 2*3, (29+31)/2 = 30 = 2*3*5, (2309+2311)/2 = 2310 = 2*3*5*7*11.
|
|
|
MATHEMATICA
|
Select[FoldList[Times, Prime@ Range@ 40], AllTrue[# + {-1, 1}, PrimeQ] &] - 1 (* Michael De Vlieger, Jul 15 2017 *)
|
|
|
CROSSREFS
|
Cf. A014545, A005234, A057704, A006794, A002110.
Sequence in context: A057208 A046842 A175905 * A057705 A237188 A086720
Adjacent sequences: A057703 A057704 A057705 * A057707 A057708 A057709
|
|
|
KEYWORD
|
nonn,bref
|
|
|
AUTHOR
|
Labos Elemer, Oct 24 2000
|
|
|
EXTENSIONS
|
Offset corrected by Arkadiusz Wesolowski, May 08 2012
|
|
|
STATUS
|
approved
|
| |
|
|
