OFFSET
1,1
COMMENTS
Or, numbers n such that n and n+2 are terms in A046704. [Zak Seidov, Feb 02 2010]
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3)=41 is in the sequence because 41, 41+2=43, 4+1=5 and 4+3=7 are primes.
a(4)=137 is in the sequence because 137, 137+2=139, 1+3+7=11 and 1+3+9=13 are primes.
MAPLE
sd:= n -> convert(convert(n, base, 10), `+`):
p:= 1: q:= 2: count:= 0: Res:= NULL:
while count < 100 do
if q = p+2 and isprime(sd(p)) and isprime(sd(q)) then
count:= count+1; Res:= Res, p
fi;
p:= q; q:= nextprime(q);
od:
Res; # Robert Israel, Apr 08 2018
MATHEMATICA
sd[n_]:=Plus@@IntegerDigits[n]; Select[Prime[Range[650]], And@@PrimeQ[{#+2, sd[#], sd[#+2]}] &] (* Jayanta Basu, May 25 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Juri-Stepan Gerasimov, Mar 16 2009
EXTENSIONS
Corrected by Juri-Stepan Gerasimov, Mar 24 2009
3299 and 4481 inserted by R. J. Mathar, Mar 27 2009
Example edited by Robert Israel, Apr 08 2018
STATUS
approved