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 A219363 #7 Feb 04 2013 15:21:07 %S A219363 1,37200,86800,170688,260400,334800,2269200,2343600,2864400,3385200, %T A219363 4947600,5291328,5294800,10155600,11048400,15884400,18897600,20422800, %U A219363 30466800,33070800,44094400,44528400,61618368,77338800,91660800 %N A219363 Numbers such that the product of divisors of n is divisible by the product of divisors of sigma(n). %C A219363 That is, numbers such that A007955(A000203(n)) | A007955(n). %C A219363 F. Luca proved that this sequence is infinite. %H A219363 F. Luca, <a href="http://jipam.vu.edu.au/v4n2/021_03.html">On the product of divisors of n and sigma(n)</a>, J. Inequal. Pure Appl. Math., Volume 4, Issue 2, Article 46, 2003. %t A219363 Select[Range[1000000], Mod[Times @@ Divisors[#], Times @@ Divisors[DivisorSigma[1, #]]] == 0 &] (* _T. D. Noe_, Nov 19 2012 *) %o A219363 (PARI) A007955(n)=if(issquare(n, &n), n^numdiv(n^2), n^(numdiv(n)/2)) %o A219363 is(n)=A007955(n)%A007955(sigma(n))==0 \\ _Charles R Greathouse IV_, Feb 04 2013 %Y A219363 Cf. A000203, A007955. %K A219363 nonn %O A219363 1,2 %A A219363 _Michel Marcus_, Nov 19 2012