cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A118571 Sophie Germain primes whose sum of digits is a prime.

Original entry on oeis.org

2, 3, 5, 11, 23, 29, 41, 83, 89, 113, 131, 173, 179, 191, 281, 359, 443, 593, 641, 683, 719, 809, 911, 953, 1013, 1019, 1031, 1103, 1439, 1451, 1499, 1583, 1811, 1901, 2003, 2063, 2069, 2339, 2351, 2393, 2399, 2753, 2939, 3299, 3329, 3389, 3413, 3491, 3761
Offset: 1

Views

Author

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

Keywords

Examples

			191 is in the sequence because it is a Sophie Germain prime and the sum of its digits 1+9+1 = 11 is a prime.
		

Crossrefs

Intersection of A005384 and A028834.
Subsequence of A046704.

Programs

  • Mathematica
    Select[Range[4000], PrimeQ[#] && PrimeQ[2*# + 1] && PrimeQ[Plus @@ IntegerDigits[#]] &] (* Amiram Eldar, Feb 08 2021 *)
    Select[Prime[Range[600]],AllTrue[{2#+1,Total[IntegerDigits[#]]},PrimeQ]&] (* Harvey P. Dale, Mar 08 2025 *)