OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MAPLE
rev:= proc(n) local L, i;
L:= convert(n, base, 10);
add(L[-i]*10^(i-1), i=1..nops(L))
end proc:
select(t -> isprime(t) and isprime(rev(t)+6), [seq(i, i=3..2000, 2)]); # Robert Israel, Dec 11 2023
MATHEMATICA
Select[Prime[Range[2, 700]], PrimeQ[FromDigits[Reverse[IntegerDigits[#]]] + 6]&] (* Vincenzo Librandi, Sep 15 2013 *)
PROG
(Magma) [p: p in PrimesInInterval(2, 1050) | IsPrime(q+6) where q is Seqint(Reverse(Intseq(p)))]; // Vincenzo Librandi, Sep 15 2013
(PARI) isok(p) = isprime(p) && isprime(fromdigits(Vecrev(digits(p)))+6); \\ Michel Marcus, Dec 11 2023
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Vincenzo Librandi, Nov 04 2009
EXTENSIONS
593 inserted, 769 removed by R. J. Mathar, Nov 08 2009
STATUS
approved