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 A176797 #8 Sep 18 2019 13:44:41 %S A176797 1,3,7,11,13,21,21,43,35,43,61,63,85,111,77,157,91,129,119,147,185, %T A176797 171,273,183,255,343,231,301,245,255,333,313,507,301,455,481,521,425, %U A176797 471,547,473,455,813,441,931,629,559 %N A176797 Antiharmonic means of divisors of antiharmonic numbers. %C A176797 Values of sigma_2(n) / sigma(n) corresponding to terms of A020487(n), where sigma_2(n) is the sum of squares of divisors of n (A001157) and sigma(n) is the sum of the divisors of n (A000203). %H A176797 Amiram Eldar, <a href="/A176797/b176797.txt">Table of n, a(n) for n = 1..10000</a> %F A176797 a(n) = (A001157(A020487(n))) / (A000203(A020487(n))). %e A176797 For n = 4; a(4) = 11 because A020487(4) = 16; A001157(16) = 341, A000203(n) = 31, antiharmonic means of divisors of 16 = 341 / 31 = 11. %t A176797 Select[DivisorSigma[2, #]/DivisorSigma[1, #] & /@ Range[1000], IntegerQ] (* _Amiram Eldar_, Sep 18 2019 *) %K A176797 nonn,look %O A176797 1,2 %A A176797 _Jaroslav Krizek_, Apr 26 2010