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%I #21 Mar 07 2023 14:33:09
%S 1,2,3,5,9,10,13,16,23,24,30,32,40,41,43,51,52,54,60,62,72,81,83,86,
%T 94,97,108,116,119,120,124,128,132,135,140,156,162,170,171,173,176,
%U 185,200,201,209,223,228,230,234,239,240,246
%N Indices of Sophie Germain primes: p and 2p+1 are primes.
%D M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 870.
%D J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 83.
%H Harvey P. Dale, <a href="/A072192/b072192.txt">Table of n, a(n) for n = 1..1000</a>
%H M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
%F a(n) = A000720(A005384(n)). - _Ridouane Oudra_, Mar 07 2023
%e 5 is element of the sequence, P(5)=11 and 2*11+1=23 is prime.
%t Select[Range[250],PrimeQ[2Prime[#]+1]&] (* _Harvey P. Dale_, Feb 22 2017 *)
%Y Cf. A005384, A000720.
%K easy,nonn
%O 1,2
%A _Miklos Kristof_, Jul 02 2002
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