This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A245779 #17 Nov 21 2023 12:17:23 %S A245779 1,2,3,4,6,8,10,12,18,24 %N A245779 Numbers n such that (n/tau(n) - sigma(n)/n) < 1. %C A245779 Numbers n such that A245776(n)/A245777(n) = n/A000005(n) - A000203(n)/n < 1. %C A245779 Finite sequence with 10 terms. %e A245779 24 is in sequence because 24/tau(24) - sigma(24)/24 = 24/8 - 60/24 = 1/2. %t A245779 a245779[n_Integer] := %t A245779 Select[Range[n], %t A245779 If[#/DivisorSigma[0, #] - DivisorSigma[1, #]/# < 1, True, False] &]; a245779[1000] (* _Michael De Vlieger_, Aug 07 2014 *) %t A245779 Select[Range[25],#/DivisorSigma[0,#]-DivisorSigma[1,#]/#<1&] (* _Harvey P. Dale_, Nov 21 2023 *) %o A245779 (Magma) [n:n in [1..1000000] | (Numerator((n /(#[d: d in Divisors(n)]))-(SumOfDivisors(n)/n))) / (Denominator((n/(#[d: d in Divisors(n)]))-(SumOfDivisors(n)/n))) lt 1] %o A245779 (PARI) %o A245779 for(n=1,10^3, if(n/numdiv(n) - sigma(n)/n < 1, print1(n,", "))) \\ _Derek Orr_, Aug 02 2014 %Y A245779 Cf. A000005, A000203, A245776, A245777, A245778, A245782. %K A245779 nonn,fini,full %O A245779 1,2 %A A245779 _Jaroslav Krizek_, Aug 02 2014