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 A074884 For a prime p, let k(p) be the least k such that 2kp+1 is prime. Sequence gives primes for which k(p) exceeds k(q) for all primes q < p. 2

%I

%S 2,7,17,19,59,167,197,227,317,457,521,1637,1861,1997,2053,3833,5227,

%T 19891,47303,54973,58603,124567,138163,170167,707467,1637429,1940777,

%U 3717731,4722079,17886697,27507569,73342163,154205101,160561133,186668543,429364379,458121431,1459411661,2140833967,4028983027,5189517859,6184586189,10352323829,36673176307

%N For a prime p, let k(p) be the least k such that 2kp+1 is prime. Sequence gives primes for which k(p) exceeds k(q) for all primes q < p.

%e a(1)=2 because k(2)=1 (2*1*2+1=5 is prime);

%e a(2)=7 because k(7)=2 (2*1*7+1=15 is not prime, 2*2*7+1=29 is prime).

%Y Cf. A117673.

%K nonn

%O 1,1

%A _Mike Oakes_, Oct 01 2002

%E a(30)-a(38) from _Don Reble_, Jan 07 2013

%E a(39)-a(44) from _Marco Frigerio_, Mar 25 2019

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Last modified June 3 05:29 EDT 2020. Contains 334798 sequences. (Running on oeis4.)