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A118573
Sophie Germain primes for which the reversal is also a Sophie Germain prime.
1
2, 3, 5, 11, 131, 191, 359, 953, 1229, 1583, 3851, 9221, 10061, 11579, 11939, 12119, 12821, 13619, 14081, 14741, 14939, 15791, 15803, 16001, 16883, 18041, 19163, 19391, 19751, 19991, 30851, 31859, 32633, 33623, 33809, 35993, 36191, 36563
OFFSET
1,1
COMMENTS
{k such that k is in A005384 and A004086(k) is in A005384}. - Jonathan Vos Post, Apr 18 2008
LINKS
EXAMPLE
359 is in the sequence because it is a Sophie Germain prime and its reversal 953 is also a Sophie Germain prime.
MATHEMATICA
Select[Prime[Range[10000]], PrimeQ[2*# + 1] && PrimeQ[FromDigits[Reverse[ IntegerDigits[ # ]]]] && PrimeQ[2*FromDigits[Reverse[IntegerDigits[ # ]]] + 1] &] (* Stefan Steinerberger, May 18 2008 *)
fQ[n_] := (rp = FromDigits@ Reverse@ IntegerDigits@n; PrimeQ[2n + 1] && PrimeQ[rp] && PrimeQ[2rp + 1]); Select[Prime@ Range@4093, fQ@# &] (* Robert G. Wilson v, May 09 2006 *)
CROSSREFS
A051835 is a subsequence.
Sequence in context: A050444 A117701 A056163 * A051835 A075883 A195815
KEYWORD
base,nonn
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), May 07 2006
EXTENSIONS
More terms from Robert G. Wilson v and Adam Panagos (adam.panagos(AT)gmail.com), May 09 2006
Edited by N. J. A. Sloane, Mar 02 2009 at the suggestion of R. J. Mathar
STATUS
approved