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 A165629 #12 Apr 01 2018 20:08:40 %S A165629 760,11020,18088,21112,58206,65262,71630,100280,123424,142688,262276, %T A165629 303212,332710,630344,679070,761390,1265096,1369120,1454060,1454260, %U A165629 1462552,1704794,2185750,2386664,2627548,2783872,2786056,2909380,2927848,5207680,5289220 %N A165629 Numbers n such that sigma(n)/phi(n) = 25/4, where sigma = A000203, phi = A000010. %C A165629 A subsequence of A011257. Contains the product m*n of relatively prime (gcd(m,n)=1) terms (m,n) in A068390 x A164648 and in A164646 x A165630. %H A165629 Donovan Johnson, <a href="/A165629/b165629.txt">Table of n, a(n) for n = 1..1000</a> %t A165629 Select[Range[5300000],4*DivisorSigma[1,#]==25*EulerPhi[#]&] (* _Harvey P. Dale_, May 09 2012 *) %o A165629 (PARI) for( i=1,1e9, sigma(i)*4-25*eulerphi(i) || print1(i", ")) %K A165629 nonn %O A165629 1,1 %A A165629 _Farideh Firoozbakht_ and _M. F. Hasler_, Sep 23 2009