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 A333871 #8 Apr 09 2020 05:23:51 %S A333871 0,1,3,1,5,3,9,1,3,5,15,3,15,9,9,1,17,3,21,5,15,15,37,3,5,15,3,9,37,9, %T A333871 39,1,25,17,27,3,39,21,27,5,45,15,57,15,9,37,83,3,9,5,33,15,67,3,45,9, %U A333871 39,37,95,9,69,39,15,1,51,25,91,17,59,27,97,3,75,39 %N A333871 Sum of the iterated absolute Möbius divisor function (A173557). %C A333871 Analogous to A092693 with the absolute Möbius divisor function (A173557) instead of the Euler totient function phi (A000010). %H A333871 Amiram Eldar, <a href="/A333871/b333871.txt">Table of n, a(n) for n = 1..10000</a> %H A333871 Daeyeoul Kim, Umit Sarp, and Sebahattin Ikikardes, <a href="https://doi.org/10.3390/math7111083">Iterating the Sum of Möbius Divisor Function and Euler Totient Function</a>, Mathematics, Vol. 7, No. 11 (2019), pp. 1083-1094. %e A333871 a(3) = A173557(3) + A173557(A173557(3)) = 2 + 1 = 3. %t A333871 f[p_, e_] := p - 1; u[1] = 1; u[n_] := Times @@ (f @@@ FactorInteger[n]); a[n_] := Plus @@ FixedPointList[u, n] - n - 1 ; Array[a, 100] %Y A333871 Cf. A092693, A173557, A333870. %K A333871 nonn %O A333871 1,3 %A A333871 _Amiram Eldar_, Apr 08 2020