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%I #8 Sep 15 2015 09:42:46
%S 0,0,1,2,4,9,19,46,110,291,822,2455,7740,25635,88849,320749,1202674,
%T 4670156,18741145,77553119,330321299,1445829174,6493985903,
%U 29891948760,140843699641,678576973614,3339785593878
%N Number of primes < square root of n!.
%t Table[PrimePi[Sqrt[n! ]], {n, 27}] (* _Robert G. Wilson v_ *)
%o (PARI) a(n)=primepi(sqrtint(n!)) \\ _Charles R Greathouse IV_, Sep 15 2015
%Y Cf. A003604.
%K nonn
%O 1,4
%A _Giovanni Teofilatto_, Oct 13 2007
%E More terms from _Stefan Steinerberger_ and _Robert G. Wilson v_, Oct 14 2007