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A104588 Product of primes less than or equal to sqrt(n). 2

%I

%S 1,1,1,2,2,2,2,2,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,30,30,30,30,30,30,30,

%T 30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,210,210,210,210,

%U 210,210,210,210,210,210,210,210,210,210,210,210,210,210,210,210,210,210

%N Product of primes less than or equal to sqrt(n).

%F a(n) = A034386(A000196(n)).

%F For n>0, #p(n) appears {(p(n+1))^2 - (p(n))^2} times [from n=(p(n))^2 to n=(p(n+1))^2 - 1, inclusive], i.e. A002110(n) appears A069482(n) times [from n=A001248(n) to n=A001248(n+1)-1, inclusive]

%p A104588 := proc(n)

%p A034386(A000196(n)) ;

%p end proc: # _R. J. Mathar_, Jul 28 2013

%o (PARI) a(n) = {pr = 1; forprime (p=2, sqrtint(n), pr *= p;); return (pr);} \\ _Michel Marcus_, Jul 28 2013

%K nonn

%O 1,4

%A _Lekraj Beedassy_, Mar 17 2005

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Last modified July 30 05:15 EDT 2021. Contains 346349 sequences. (Running on oeis4.)