OFFSET
1,1
COMMENTS
Infinite under Dickson's conjecture. [Charles R Greathouse IV, Jul 24 2011]
LINKS
Andrea Raffetti, Table of n, a(n) for n = 1..999
EXAMPLE
5 is in the list because 5*6=30, 5*36=180 and both fall between a pair of twin primes (29,31 and 179,181).
MATHEMATICA
Select[Range[3100], And@@PrimeQ[{6#+1, 6#-1, 36#+1, 36#-1}]&] (* Harvey P. Dale, Jul 27 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Andrea Raffetti, Jul 11 2011
STATUS
approved