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 A163375 #11 Sep 08 2022 08:45:46 %S A163375 1,1,3,3,4,3,7,4,7,4,7,4,12,7,7,7,6,7,12,7,12,7,7,7,12,12,12,12,12,7, %T A163375 15,6,12,6,15,12,13,12,15,6,15,12,15,12,15,7,7,6,15,12,12,15,12,12,15, %U A163375 15,13,12,7,6,28,15,13,12,18,12,15,12,12,15,15,15 %N A163375 a(n) = sigma(tau(phi(n))). %H A163375 G. C. Greubel, <a href="/A163375/b163375.txt">Table of n, a(n) for n = 1..1000</a> %F A163375 a(n) = A000203(A000005(A000010(n))) = A000203(A062821(n)) = A062069(A000010(n)). %t A163375 DivisorSigma[1, DivisorSigma[0, EulerPhi[Range[100]]]] (* _G. C. Greubel_, Dec 20 2016 *) %o A163375 (PARI) vector(100, n, sigma(numdiv(eulerphi(n)))) \\ _G. C. Greubel_, Dec 20 2016 %o A163375 (Magma) [SumOfDivisors(NumberOfDivisors(EulerPhi(n))): n in [1..80]]; // _Vincenzo Librandi_, Dec 20 2016 %Y A163375 Cf. A000005, A000010, A000203, A062069, A062821. %K A163375 nonn %O A163375 1,3 %A A163375 _Jaroslav Krizek_, Jul 25 2009