OFFSET
1,1
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..1000
EXAMPLE
98303927 is a member because 98303927 = (98303903 + 98303951)/2 = (98303897 + 98303957)/2 = (98303873 + 98303981)/2 = (98303867 + 98303987)/2.
MATHEMATICA
a = {}; Do[p = 2Prime[n]; If[p == Prime[n - 1] + Prime[n + 1], If[ p == Prime[n - 2] + Prime[n + 2], If[p == Prime[n - 3] + Prime[n + 3], If[p == Prime[n - 4] + Prime[n + 4], Print[p/2]; AppendTo[a, p/2]]]]], {n, 6, 117039731}]; a
Select[Partition[Prime[Range[207405000]], 9, 1], (#[[1]]+#[[9]])/2 == (#[[2]]+ #[[8]])/2 == (#[[3]]+#[[7]])/2==(#[[4]]+#[[6]])/2==#[[5]]&][[All, 5]] (* Harvey P. Dale, Dec 27 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jun 28 2004
EXTENSIONS
More terms from Jud McCranie, Sep 29 2006
STATUS
approved