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 A135667 Least k such that k!! > prime(1)*prime(2)*...*prime(n) where prime(n) is the n-th prime. 2

%I

%S 3,4,6,8,10,12,14,16,19,21,23,25,28,30,32,34,37,39,41,43,46,48,50,52,

%T 55,57,59,62,64,66,68,71,73,75,78,80,82,84,87,89,91,94,96,98,101,103,

%U 105,108,110,112,114,117,119,121,124,126,128,131,133,135,138

%N Least k such that k!! > prime(1)*prime(2)*...*prime(n) where prime(n) is the n-th prime.

%o (PARI) dbf(n) = prod(i = 0, floor((n-1)/2), n - 2*i );

%o a(n) = pr = prod(i = 1, n, prime(i)); k = 1; while(dbf(k) <= pr, k++); k; \\ _Michel Marcus_, Oct 13 2013

%Y Cf. A002110, A006882, A073071.

%K nonn

%O 1,1

%A _Zak Seidov_, May 01 2008

%E More terms from _Michel Marcus_, Oct 13 2013

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Last modified May 7 12:38 EDT 2021. Contains 343650 sequences. (Running on oeis4.)