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 A171421 #10 Feb 29 2020 03:42:47 %S A171421 1,2,2,4,6,22,8,36,12,46,52,16,66,24,78,82,88,96,32,36,112,126,130,44, %T A171421 40,156,162,166,172,48,64,60,210,222,72,232,64,250,256,262,72,276,92, %U A171421 292,306,96,316,330,336,112,352,358,366,372,378,382,388,396,400,408 %N A171421 Euler totient function of the n-th single or isolated number. %H A171421 Amiram Eldar, <a href="/A171421/b171421.txt">Table of n, a(n) for n = 1..10000</a> %F A171421 a(n) = A000010(A167706(n)). %Y A171421 Cf. A000010, A167706, A168543. %K A171421 nonn,less %O A171421 1,2 %A A171421 _Juri-Stepan Gerasimov_, Dec 08 2009 %E A171421 More terms from _Amiram Eldar_, Feb 29 2020