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A117848 Least K such that K*p(n)#-1 is the first of twin primes and 2*(K*p(n)#-1)+1 is prime, so K*p(n)#-1 is the first of twin primes and a Sophie Germain prime. 0

%I #8 Oct 08 2022 08:33:40

%S 2,1,1,2,5,9,17,11,4,16,61,118,141,680,37,430,401,576,885,953,358,

%T 1857,1376,91,798,209,3014,5707,2327,3013,923,9437,403,9392,356,3161,

%U 266,2012,2796,4095,6362,3008,12227,18277,25353,3682,18414,21783,1889

%N Least K such that K*p(n)#-1 is the first of twin primes and 2*(K*p(n)#-1)+1 is prime, so K*p(n)#-1 is the first of twin primes and a Sophie Germain prime.

%e 2*2-1 = 3, 3 5 twin primes and 2*3+1=7 prime, so 3 is the first of twin primes and is also a Sophie Germain prime.

%K nonn

%O 1,1

%A _Pierre CAMI_, May 01 2006

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