OFFSET
1,1
COMMENTS
EXAMPLE
260 is an interprime and 260/20 = 13 is prime.
MATHEMATICA
s=20; Select[Table[(Prime[n+1]+Prime[n])/2, {n, 2, 14000}], PrimeQ[ #/s]&]
Select[Total[#]/2&/@Partition[Prime[Range[5000]], 2, 1], PrimeQ[#/20]&] (* Harvey P. Dale, Dec 15 2023 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Zak Seidov, Sep 12 2002
STATUS
approved