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A128661 Numbers k such that p(k+1)# + p(k)# - p(k-1)# - 1 is prime where p(i)# = product of first i primes = A002110(i).

%I A128661 #10 Jul 23 2023 01:48:13
%S A128661 3,7,14,15,21,32,34,47,67,69,174,369,568,3193,3882,5426
%N A128661 Numbers k such that p(k+1)# + p(k)# - p(k-1)# - 1 is prime where p(i)# = product of first i primes = A002110(i).
%t A128661 Flatten[Position[Partition[Rest[FoldList[Times,1,Prime[Range[ 600]]]],3,1], _?(PrimeQ[#[[3]]+#[[2]]-#[[1]]-1]&),{1},Heads-> False]]+1 (* _Harvey P. Dale_, May 26 2013 *)
%Y A128661 Cf. A002110, A128420, A128421, A128657, A128658, A128659, A128660, A128662.
%K A128661 nonn,more
%O A128661 1,1
%A A128661 _Pierre CAMI_, Mar 19 2007
%E A128661 a(14)-a(16) from _Michael S. Branicky_, Jul 22 2023