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 A065394 #17 Feb 20 2025 06:31:15
%S A065394 1,5,8,14,22,25,31,48,56,73,78,80,138,159,163,210,240,248,312,314,474,
%T A065394 482,634,648,684,723,836,896,978,1026,1134,1184,1320,1344,1410,1424,
%U A065394 1608,1686,1760,1776,1862,2226,2624,2824,2936,3024,3120,3280,3460,3660
%N A065394 Increasing values of A065395: a(n) = A065395(A065393(n)).
%H A065394 Amiram Eldar, <a href="/A065394/b065394.txt">Table of n, a(n) for n = 1..2000</a> (terms 1..500 from Harry J. Smith)
%F A065394 a(n) = A000203(A000010(A065393(n))) - A000010(A000203(A065393(n))).
%t A065394 a=0; s=0; Do[s=DivisorSigma[1, EulerPhi[n]]-EulerPhi[DivisorSigma[1, n]]; If[s>a, a=s; Print[s]], {n, 1, 10000}]; (* Output is s. *)
%o A065394 (PARI) { n=r=0; for (m=1, 10^9, x=sigma(eulerphi(m)) - eulerphi(sigma(m)); if (x > r, r=x; write("b065394.txt", n++, " ", x); if (n==500, return)) ) } \\ _Harry J. Smith_, Oct 18 2009
%Y A065394 Cf. A000010, A000203, A065393, A065395.
%K A065394 nonn
%O A065394 1,2
%A A065394 _Labos Elemer_, Nov 05 2001