OFFSET
1,1
EXAMPLE
167 is in the sequence because (1) it is a Chen prime and (2) the digital root 5 is also a Chen prime.
MATHEMATICA
digitalRoot[n_Integer?Positive] := FixedPoint[Plus@@IntegerDigits[#] &, n]); chenPrimeQ[x_] := PrimeQ[x] && Plus@@Last/@FactorInteger[x+2] <= 2; Select[Range[1000], chenPrimeQ[#] && chenPrimeQ[digitalRoot[#]]&] (* Vladimir Joseph Stephan Orlovsky, Apr 30 2011, with a function by Eric W. Weisstein *)
PROG
(PARI) isA118723(n)=[0, 0, 1, 1, 0, 1, 0, 1, 0][n%9+1]&isprime(n)&bigomega(n+2)<3 \\ Charles R Greathouse IV, Apr 30 2011
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), May 21 2006
STATUS
approved