OFFSET
1,1
EXAMPLE
a(2)=4 because 7 and 11 are prime neighbors of 2*4 and 11-7=4.
MATHEMATICA
Table[Prime[PrimePi[4n]+1]-Prime[PrimePi[4n]], {n, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Apr 01 2006
STATUS
approved