OFFSET
1,1
EXAMPLE
a(1)=6 because first prime 2 occurs after 314159,
a(2)=2 because second prime 3 occurs after 26,
a(3)=0 because third prime 5 is adjacent to 3, ...
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jani Melik, Aug 01 2007
STATUS
approved