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A083541 Values of y from solutions to sigma(x+1)*sigma(x)=y^2, where A083539(x) = y^2 is a square number. 2

%I #9 Apr 09 2021 03:50:52

%S 24,48,84,264,288,312,336,576,960,1152,1440,1440,1440,1440,1680,2100,

%T 2160,2688,2640,3360,3024,3360,3360,4320,4320,5376,4032,4464,5040,

%U 4788,6048,7392,6720,6840,7644,6300,7440,7560,7020,10080,10080,8064,10080

%N Values of y from solutions to sigma(x+1)*sigma(x)=y^2, where A083539(x) = y^2 is a square number.

%H Amiram Eldar, <a href="/A083541/b083541.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = sqrt(sigma(A083540(n)) * sigma(1+A083540(n))).

%t Do[s=Sqrt[DivisorSigma[1, n+1]*DivisorSigma[1, n]]; If[IntegerQ[s], Print[s]], {n, 1, 5000}]

%Y Cf. A000203, A083539, A083540, A083538, A060780, A060781.

%K nonn

%O 1,1

%A _Labos Elemer_, May 21 2003

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Last modified September 16 15:08 EDT 2024. Contains 375976 sequences. (Running on oeis4.)