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 A039784 #7 Feb 24 2021 22:51:10 %S A039784 1,2,12,48,5832 %N A039784 phi(n) is equal to the product of the dual prime-power components of n. %e A039784 phi(5832)=1944, 5832=2^3*3^6, (3^2)*(6^3)=1944. %Y A039784 Cf. A000010, A008477. %K A039784 nonn %O A039784 1,2 %A A039784 _Olivier Gérard_ %E A039784 No others < 7*10^7. - _Naohiro Nomoto_, Jun 23 2001