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%I #31 May 07 2018 03:52:25
%S 1,2,6,15,35,385,1001,17017,46189,1062347,30808063,955049953,
%T 3212440751,131710070791,435656388001,20475850236047,1085220062510491,
%U 64027983688118969,229747470880897477,15393080549020130959,57521511525285752531,4199070341345859934763,331726556966322934846277
%N a(n) = Primorial(n) / Product_{k prime<n} k.
%C Sum_{n>=0} 1/a(n) = 1.765582555581609270...
%F a(0)=1, for n > 0 a(n) = A002110(n) / A034386(n-1).
%e a(5) = 2*3*5*7*11 / 2*3 = 385.
%o (PARI) a(n) = prod(k=1, n, prime(k))/prod(k=1, n-1, if (isprime(k), k, 1)); \\ _Michel Marcus_, Mar 26 2018
%Y Cf. A002110, A034386.
%K nonn
%O 0,2
%A _Pedro Caceres_, Mar 24 2018
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