A118504 Sophie Germain primes whose sum of digits is also a Sophie Germain prime.

2, 3, 5, 11, 23, 29, 41, 83, 113, 131, 173, 191, 281, 443, 641, 911, 1013, 1019, 1031, 1103, 1451, 1499, 1811, 1901, 2003, 2063, 2351, 2399, 2939, 3299, 3389, 3413, 4793, 4919, 5051, 5231, 5279, 5303, 5501, 5639, 6113, 6131, 6269, 6449, 7079, 7103, 7121, 7211

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)

Example

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

Mathematica

sgpQ[n_]:=Module[{c=Total[IntegerDigits[n]]}, And@@PrimeQ[{2n+1, c, 2c+1}]]; Select[Prime[Range[1000]], sgpQ] (* Harvey P. Dale, Oct 14 2012 *)

Crossrefs

Subsequence of A118571.

Cf. A005384.

Sequence in context: A246857 A005384 A118571 * A215714 A350100 A038905

Adjacent sequences: A118501 A118502 A118503 * A118505 A118506 A118507

Keyword

base,nonn

Author

Luc Stevens (lms022(AT)yahoo.com), May 06 2006; corrected May 12 2006

Extensions

Corrected by T. D. Noe, Oct 25 2006

Corrected by Harvey P. Dale, Oct 14 2012

Status

approved