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 A087293 Numbers k such that ((prime(k)*prime(k+1))^2 + 1)/2 is prime. 1

%I

%S 2,3,6,14,27,30,35,37,44,55,101,106,118,127,137,140,154,172,184,233,

%T 248,256,260,289,383,389,425,461,463,485,500,503,513,552,584,610,617,

%U 630,642,696,706,714,737,746,819,884,926,952,964,978,1004,1008,1019,1027

%N Numbers k such that ((prime(k)*prime(k+1))^2 + 1)/2 is prime.

%C Resulting primes are in A087294.

%e 2 is in the sequence because ((prime(2)*prime(3))^2 + 1)/2 = ((3*5)^2 + 1)/2 = 113 is prime.

%Y Cf. A086893, A087294.

%K nonn

%O 1,1

%A _Ray Chandler_, Aug 31 2003

%E Offset changed to 1 by _Jinyuan Wang_, Aug 06 2021

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Last modified January 28 04:11 EST 2022. Contains 350654 sequences. (Running on oeis4.)