OFFSET
1,1
EXAMPLE
13*2+3=29 prime
13*2+5=31 prime P(1)#=2, 13*P(1)#+P(2) and 13*P(1)#+P(3) are primes so k(1)=13
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Oct 19 2004
STATUS
approved