A082565 -id:A082565

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A082520

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

+10
3

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

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OFFSET

1,1

COMMENTS

Subsequence of A051835 (intersection of A002385 and A005384).

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

EXAMPLE

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

MATHEMATICA

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

CROSSREFS

Cf. A002385, A005384, A051835.

The associated primes are listed in A082565.

KEYWORD

base,nonn

AUTHOR

Lekraj Beedassy, Apr 30 2003

STATUS

approved

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