OFFSET
1,1
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1) = 4 = (3+5)/2.
MATHEMATICA
t = Select[Prime[Range[500]], PrimeQ[# - 2] || PrimeQ[# + 2] &]; (Most[t] + Rest[t])/2 (* T. D. Noe, Aug 07 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Aug 02 2009
EXTENSIONS
35 replaced by 36 - R. J. Mathar, Aug 06 2009
STATUS
approved