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 A039783 #10 Aug 03 2017 01:29:02 %S A039783 5,17,51,73,109,433,17408,21601,121501,1350001,3294173,9376762501 %N A039783 phi(n) is equal to the product of the dual prime-power components of n-1 (i.e., A008477(n-1)). %C A039783 a(13) > 3*10^10. - _Donovan Johnson_ %e A039783 phi(17408) = 8192, 17407 = 13^2*103^1, (2^13)*(1^103) = 8192. %Y A039783 Cf. A000010, A008477. %K A039783 nonn %O A039783 1,1 %A A039783 _Olivier Gérard_ %E A039783 More terms from _Naohiro Nomoto_, Jun 24 2001 %E A039783 a(12) from _Donovan Johnson_, Nov 14 2010