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%I #14 Jan 06 2024 09:20:52
%S 2,4,3,6,4,6,10,12,5,9,14,8,6,20,22,15,12,7,10,26,18,28,30,21,8,34,12,
%T 15,38,20,9,42,44,30,46,24,14,33,10,52,18,28,58,39,60,11,62,25,42,16,
%U 66,45,68,70,12,21,74,30,76,51,78,40,18,82,84,13,57,86
%N Let m = A013929(n); then a(n) = smallest k such that m divides k^2.
%H Amiram Eldar, <a href="/A015049/b015049.txt">Table of n, a(n) for n = 1..10000</a>
%H Henry Ibstedt, <a href="http://www.gallup.unm.edu/~smarandache/Ibstedt-surfing.pdf">Surfing on the Ocean of Numbers</a>, Erhus Univ. Press, Vail, 1997.
%F a(n) = A019554(A013929(n)).
%F Sum_{k=1..n} a(k) ~ c * n^2 / 2, where c = zeta(2)*(zeta(3)-1)/(zeta(2)-1)^2 = 0.799082... . - _Amiram Eldar_, Jan 06 2024
%t f[p_, e_] := p^Ceiling[e/2]; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; s /@ Select[Range[200], !SquareFreeQ[#] &] (* _Amiram Eldar_, Feb 10 2021 *)
%o (PARI) lista(kmax) = {my(f); for(k = 2, kmax, f = factor(k); if(!issquarefree(f), print1(k/core(f, 1)[2], ", ")));} \\ _Amiram Eldar_, Jan 06 2024
%Y Cf. A013929, A015050, A015051, A019554.
%K nonn
%O 1,1
%A R. Muller
%E Description corrected by Diego Torres (torresvillarroel(AT)hotmail.com), Jun 23 2002
%E Offset corrected by _Amiram Eldar_, Feb 10 2021
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