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Numbers k in A008864 such that k^2 - k - 1 is prime.
1

%I #13 Dec 19 2022 03:31:44

%S 3,4,6,12,14,20,32,42,54,60,84,90,102,104,132,150,164,182,192,194,200,

%T 234,242,264,282,332,350,374,402,420,432,434,450,462,464,500,542,570,

%U 572,660,674,684,692,710,740,744,762,770,810,864,882,942,1014,1040

%N Numbers k in A008864 such that k^2 - k - 1 is prime.

%C See A053185 for the primes associated with a(n).

%F a(n) = A053184(n) + 1.

%o (PARI) isok(k) = isprime(k-1) && isprime(k^2-k-1); \\ _Michel Marcus_, Dec 19 2022

%Y Cf. A008864, A053184, A136242.

%K nonn

%O 1,1

%A _Lekraj Beedassy_, Dec 24 2007

%E a(20)=194 inserted by _Georg Fischer_, Dec 18 2022