

A118504


Sophie Germain primes for which the sum of the digits is also a Sophie Germain prime.


1



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
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000


EXAMPLE

191 is in the sequence because (1) it is a Sophie Germain prime and (2) 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

Cf. A005384.
Sequence in context: A246857 A005384 A118571 * A215714 A038905 A019405
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



