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A065734 Largest square <= sigma(n).

%I A065734 #20 Dec 13 2024 12:38:58
%S A065734 1,1,4,4,4,9,4,9,9,16,9,25,9,16,16,25,16,36,16,36,25,36,16,49,25,36,
%T A065734 36,49,25,64,25,49,36,49,36,81,36,49,49,81,36,81,36,81,64,64,36,121,
%U A065734 49,81,64,81,49,100,64,100,64,81,49,144,49,81,100,121,81,144,64,121,81,144
%N A065734 Largest square <= sigma(n).
%H A065734 Harry J. Smith, <a href="/A065734/b065734.txt">Table of n, a(n) for n = 1..1000</a>
%F A065734 a(n) = A048760(A000203(n)).
%t A065734 Table[Floor[Sqrt[DivisorSigma[1,n]]]^2,{n,70}] (* _Harvey P. Dale_, Oct 05 2015 *)
%o A065734 (PARI) a(n) = { sqrtint(sigma(n))^2 } \\ _Harry J. Smith_, Oct 28 2009
%o A065734 (Maxima)
%o A065734 A000203(n) := divsum(n) ;
%o A065734 A048760(n) := (floor(sqrt(n)))^2 ;
%o A065734 A065734(n) := A048760(A000203(n)) ;
%o A065734 for n from 1 thru 10 do print(A065734(n)) ; /* _R. J. Mathar_, Feb 13 2012 */
%Y A065734 Cf. A048760, A000203, A065730-A065741.
%K A065734 easy,nonn
%O A065734 1,3
%A A065734 _Labos Elemer_, Nov 15 2001
%E A065734 Previous Mathematica program replaced by _Harvey P. Dale_, Oct 05 2015