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%I #11 Apr 22 2012 13:41:07
%S 1,1,4,4,10,1,351,240,620,1362,2184,46,2944
%N Let p(1) = 13. Then a(n) is the least k such that p(n+1) = (k*p(n))^2 + k*p(n) - 1 is prime.
%C p sequence starts 181, 32941, 17361883459, 4822959955971812408731, ...
%C a(13) corresponds to a 12,272-digit BPSW-probable prime. - _Charles R Greathouse IV_, Apr 22 2012
%o (PARI) p=13;for(i=1,9,k=1;while(!ispseudoprime(t=(k*p)^2+k*p-1),k++); p=t; print1(k", ")) \\ _Charles R Greathouse IV_, Apr 20 2012
%K nonn
%O 1,3
%A _Pierre CAMI_, Jul 01 2006
%E a(9)-a(12) from _Charles R Greathouse IV_, Apr 20 2012
%E a(13) from _Charles R Greathouse IV_, Apr 22 2012