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 A333169 #14 Nov 21 2020 14:12:56
%S A333169 1,1,4,4,16,12,36,20,48,40,100,60,112,64,196,112,256,112,240,180,400,
%T A333169 192,384,208,576,312,676,288,624,420,832,432,800,432,1056,612,1296,
%U A333169 544,1088,760,1600,812,1408,720,1776,1012,2016,768,1840,1200,2400,1300,2160
%N A333169 a(n) = phi(n^2 + 1), where phi is the Euler totient function (A000010).
%D A333169 Steven R. Finch, Mathematical Constants II, Encyclopedia of Mathematics and Its Applications, Cambridge University Press, Cambridge, 2018, p. 166.
%H A333169 Amiram Eldar, <a href="/A333169/b333169.txt">Table of n, a(n) for n = 0..10000</a>
%F A333169 a(n) = A000010(A002522(n)).
%e A333169 a(0) = phi(0^2 + 1) = phi(1) = 1.
%t A333169 Table[EulerPhi[k^2 + 1], {k, 0, 100}]
%o A333169 (PARI) a(n) = eulerphi(n^2+1); \\ _Michel Marcus_, Mar 10 2020
%Y A333169 Cf. A000010, A002522, A067720, A193432, A193433, A333167.
%K A333169 nonn
%O A333169 0,3
%A A333169 _Amiram Eldar_, Mar 09 2020