OFFSET
1,1
EXAMPLE
The prime 2971 is from the prime 971 by pre-concatenating with 2.
MATHEMATICA
Select[Map[FromDigits,
Map[Join[{2}, #] &, IntegerDigits[Prime[Range[200]]]]], PrimeQ[#] &] (* Robert Price, Mar 31 2019 *)
PROG
(PARI) terms(n) = my(i=0, cc=[]); forprime(p=1, , cc=eval(concat("2", Str(p))); if(ispseudoprime(cc), print1(cc, ", "); i++); if(i==n, break))
/* Print initial 40 terms as follows: */
terms(40) \\ Felix Fröhlich, Mar 31 2019
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Sep 09 2009
EXTENSIONS
2269 inserted by R. J. Mathar, Sep 21 2009
STATUS
approved