A118573 Sophie Germain primes for which the reversal is also a Sophie Germain prime.

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

Author

Luc Stevens (lms022(AT)yahoo.com), May 07 2006

Keywords

• base
• nonn

Comments

{k such that k is in A005384 and A004086(k) is in A005384}. - Jonathan Vos Post, Apr 18 2008

Examples

			359 is in the sequence because it is a Sophie Germain prime and its reversal 953 is also a Sophie Germain prime.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A004086, A005384.

A051835 is a subsequence.

Programs

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 *)

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