OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..500
EXAMPLE
The average of prime(4) and prime(5) is (7 + 11)/2 = 3^2, so 4 is a term of the sequence.
MATHEMATICA
Select[Range[10^4], IntegerQ[Sqrt[(Prime[ # ] + Prime[ # + 1])/2]] &]
Position[Mean/@Partition[Prime[Range[10000]], 2, 1], _?(IntegerQ[ Sqrt[ #]]&)]//Flatten (* Harvey P. Dale, May 17 2017 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Joseph L. Pe, Oct 25 2002
STATUS
approved