cp's OEIS Frontend

A085087 a(1) = 1; for n>1, a(n) = a(n-1)*n if n is prime, a(n) = a(n-1)/n if n is composite dividing a(n-1) else a(n) = a(n-1).

%I A085087 #10 May 21 2015 17:23:41
%S A085087 1,2,6,6,30,5,35,35,35,35,385,385,5005,5005,5005,5005,85085,85085,
%T A085087 1616615,1616615,1616615,1616615,37182145,37182145,37182145,37182145,
%U A085087 37182145,37182145,1078282205,1078282205,33426748355,33426748355
%N A085087 a(1) = 1; for n>1, a(n) = a(n-1)*n if n is prime, a(n) = a(n-1)/n if n is composite dividing a(n-1) else a(n) = a(n-1).
%H A085087 Ivan Neretin, <a href="/A085087/b085087.txt">Table of n, a(n) for n = 1..500</a>
%F A085087 Let k be the number of members of A089581 that are <= n; then a(n) = A034386(n)/A099788(k). - _David Wasserman_, Jan 25 2005
%t A085087 a = {1}; Do[AppendTo[a, If[PrimeQ[n], a[[-1]]*n, If[Divisible[a[[-1]], n], a[[-1]]/n, a[[-1]]]]], {n, 2, 32}]; a (* _Ivan Neretin_, May 21 2015 *)
%o A085087 (PARI) print1(k=1); for(n=2,99, if(isprime(n), k*=n, if(k%n==0, k/=n)); print1(", "k)) \\ _Charles R Greathouse IV_, May 21 2015
%Y A085087 Cf. A034386, A089581, A099788.
%K A085087 nonn
%O A085087 1,2
%A A085087 _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jul 02 2003
%E A085087 More terms from _David Wasserman_, Jan 25 2005