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A118504
Sophie Germain primes whose sum of 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
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
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