A082520 Palindromic Sophie Germain primes: both p and 2p+1 are palindromic primes.

2, 3, 5, 191, 19391, 38183, 1508051, 1609061, 1628261, 3717173, 3916193, 161535161, 161838161, 170646071, 172747271, 182949281, 190909091, 352909253, 354848453, 360818063, 364636463, 15052625051, 15150805151, 15253635251

Offset: 1

Author

Lekraj Beedassy, Apr 30 2003

Keywords

• base
• nonn

Comments

Subsequence of A051835 (intersection of A002385 and A005384).

Examples

			3916193 is in the sequence because both 3916193 and 2*3916193 + 1 = 7832387 are palindromic primes.
		

References

• H. Dubner, "Palindromic Sophie Germain primes", Journal of Recreational Mathematics, Vol. 26(1):38-41 1994 Baywood Inc. NY

Links

• Dmitry Petukhov, Table of n, a(n) for n = 1..804 (terms up to 10^15).
• H. Dubner, Palindromic Sophie Germain Primes

Crossrefs

Cf. A002385, A005384, A051835.

The associated primes are listed in A082565.

Programs

Mathematica

Select[Prime@Range@1000000,PalindromeQ@#&&PalindromeQ[2#+1]&&PrimeQ[2#+1]&] (* Giorgos Kalogeropoulos, May 14 2021 *)