OFFSET
1,1
EXAMPLE
a(1)=5 because 1st primes (6*1-1=5 and 6*1+1=7) are a pair of twin primes;
a(2)=11 because 2nd primes (6*2-1=11 and 6*2+1=13) are a pair of twin primes;
a(3)=17 because 3rd primes (6*3-1=17 and 6*3+1=19) are a pair of twin primes;
a(4)=41 because 6th primes (6*7-1=41 and 6*7+1=43) are a pair of twin primes;
a(5)=227 because 24th primes (6*38-1=227 and 6*38+1=229) are a pair of twin primes.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Juri-Stepan Gerasimov, Dec 16 2009
EXTENSIONS
Incorrect a(6) removed by R. J. Mathar, Jun 07 2010
STATUS
approved