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%I #10 Nov 17 2018 21:40:45
%S 0,8,125,4222,258659,25306159,3610490130,706003793908,181035032176791
%N a(n) is the number of primes between n! and (2n)!.
%e a(2) = 8 as pi(24) = 9 and pi(2) = 1.
%p with(numtheory): 0,seq(pi((2*n)!)-pi(n!),n=2..5); # _Emeric Deutsch_, Jul 31 2005
%t a[n_] := PrimePi[(2n)! - 1] - PrimePi[n! ]; Table[a[n], {n, 1, 8}] (* _Ryan Propper_, Sep 11 2005 *)
%Y Cf. A076959.
%K nonn
%O 1,2
%A _Amarnath Murthy_, Oct 21 2002
%E Corrected and extended by _Emeric Deutsch_, Jul 31 2005
%E 2 further terms from _Ryan Propper_, Sep 11 2005
%E a(9) from _Donovan Johnson_, Mar 10 2010
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