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%I #4 Jun 25 2013 16:50:05
%S 41,91,299,341
%N Numbers n such that n!!-8 and n!!+8 are two consecutive primes.
%C n is in the sequence iff n!!-8 and n!!+8 are primes and the four numbers n!!-2,n!!+2, n!!-4 & n!!+4 are composites. It's interesting that related to the term 341 we can say 341!!-(3+4+1) and 341!!+(3+4+1) are two consecutive primes with length 341+prime(3+4+1). Conjecture: 341 is the largest term of this sequence.
%e 341 is in the sequence because 341!!-8 and 341!!+8 are primes and the four numbers 341!!-2, 341!!+2, 341!!-4 & 341!!+4 are composites.
%t Select[Range[5,500],PrimeQ[ #!!-8]&&PrimeQ[ #!!+8]&&!PrimeQ[ #!!-4] &&!PrimeQ[ #!!+4]&&!PrimeQ[ #!!-2]&&!PrimeQ[ #!!+2]&]
%t n8pQ[n_]:=Module[{x=n!!},PrimeQ[x-8]&&NextPrime[x-8]==x+8]; Select[Range[ 350],n8pQ] (* _Harvey P. Dale_, Jun 25 2013 *)
%Y Cf. A076188.
%K nonn
%O 1,1
%A _Farideh Firoozbakht_, Nov 19 2006