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Let p(n) = upper member of n-th pair of twin primes; sequence gives a(n) = p(n)!/2.
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%I #8 Aug 23 2024 23:21:21

%S 60,2520,3113510400,60822550204416000,

%T 4111419327088961408862781440000000,

%U 30207631531686917818677566034256998753632256000000000

%N Let p(n) = upper member of n-th pair of twin primes; sequence gives a(n) = p(n)!/2.

%t #!/2&/@Select[Partition[Prime[Range[50]],2,1],#[[2]]-#[[1]]==2&][[All,2]] (* _Harvey P. Dale_, Nov 27 2016 *)

%o (PARI) tpperm2(n) = { forprime(x=3,n, if(isprime(x-2), print1(x!/2" ") ) ) }

%K easy,nonn

%O 0,1

%A _Cino Hilliard_, May 18 2003