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%I #9 May 14 2020 16:35:47
%S 2,11,197,521,3571,20633237,54018521,370248451,119218851371,
%T 5600748293801,10420180999117162547,412670427844921037470771,
%U 258899611203303418721656157249445530046830073044201152332257717521
%N Primes of the form L(k)*L(k+1)-1, where L(k) is the k-th Lucas number (A000032).
%e 11 is in the sequence because 11 = 3*4-1 = L(2)*L(3)-1.
%t Array[LucasL@ # LucasL[# + 1] - 1 &, {160}] /. n_ /; CompositeQ@ n -> Nothing (* _Michael De Vlieger_, Apr 07 2016 *)
%t Select[Times@@@Partition[LucasL[Range[200]],2,1]-1,PrimeQ] (* _Harvey P. Dale_, May 14 2020 *)
%o (PARI)
%o lucas(n) = fibonacci(n+1) + fibonacci(n-1)
%o L=List(); for(k=1, 200, if(isprime(p=lucas(k)*lucas(k+1)-1), listput(L, p))); Vec(L)
%Y Cf. A000032, A271430.
%K nonn
%O 1,1
%A _Colin Barker_, Apr 07 2016
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