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A119317 n-th divisor of A087134(n), the smallest number whose n-th divisor is prime (for n > 1).

%I A119317 #15 Feb 16 2019 21:10:30
%S A119317 1,2,3,5,7,7,13,13,19,17,23,31,29,31,41,61,61,61,47,61,73,97,127,71,
%T A119317 97,107,127,149,173,211,127,97,107,211,127,149,173,181,211,257,281,
%U A119317 317,181,421,241,257,281,317,337,367,421,509,563,631,727,421,487,509
%N A119317 n-th divisor of A087134(n), the smallest number whose n-th divisor is prime (for n > 1).
%H A119317 Amiram Eldar, <a href="/A119317/b119317.txt">Table of n, a(n) for n = 1..10000</a>
%t A119317 a[1] = 1; a[n_] := Module[{k = 1, d}, While[DivisorSigma[0, k] < n || ! PrimeQ[d = Divisors[k][[n]]], k++]; d]; Array[a, 30]  (* _Amiram Eldar_, Feb 06 2019 *)
%o A119317 (Maxima) A119317(n) := block(
%o A119317    if equal(n,1) then
%o A119317       return(1),
%o A119317    for i : 1 do (
%o A119317       idv : listify(divisors(i)),
%o A119317       if length(idv) >= n then (
%o A119317          if primep(idv[n]) then
%o A119317             return(idv[n])
%o A119317         )
%o A119317      )
%o A119317 )$ /* _R. J. Mathar_, Mar 13 2012 */
%Y A119317 Cf. A000040, A119318, A119319.
%K A119317 nonn
%O A119317 1,2
%A A119317 _Reinhard Zumkeller_, May 15 2006
%E A119317 More terms from _Amiram Eldar_, Feb 06 2019