OFFSET
1,1
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
EXAMPLE
14=2*7 is a term as 41 is prime but 14 is not;
13 is not a term as its reversal is also a prime.
MATHEMATICA
Select[ Range[169], Xor[ PrimeQ[ # ], PrimeQ[ FromDigits[ Reverse[ IntegerDigits[ # ]]]]] & ]
PROG
(PARI) { n=0; for (m=0, 3910, x=m; r=0; while (x>0, d=x-10*(x\10); x\=10; r=r*10 + d); if ((isprime(m) + isprime(r)) == 1, write("b061365.txt", n++, " ", m)) ) } \\ Harry J. Smith, Jul 21 2009
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, May 21 2002
STATUS
approved