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 A333262 #7 Mar 14 2020 04:43:23 %S A333262 0,1,2,3,4,4,5,5,6,5,6,6,7,6,7,7,8,8,9,7,8,7,8,8,9,7,8,9,10,8,9,9,9,9, %T A333262 10,10,11,8,10,9,10,10,11,9,11,9,10,10,12,10,11,11,12,10,11,9,10,9,10, %U A333262 10,11,10,10,12,10,11,12,11,11,11,12,13,14,9,11,11 %N A333262 Number of steps to reach 1 by iterating the alternating sum of divisors function A071324 starting from n. %H A333262 Amiram Eldar, <a href="/A333262/b333262.txt">Table of n, a(n) for n = 1..10000</a> %F A333262 a(n) = 0 if n = 1 and a(n) = a(A071324(n)) + 1 otherwise. %e A333262 a(3) = 2 since it takes 2 iterations of A071324 to reach from 3 to 1: 3 -> 2 -> 1. %t A333262 f[n_] := Plus @@ (-(d = Divisors[n])*(-1)^(Range[Length[d],1,-1])); a[n_] := Length @ FixedPointList[f,n] - 2; Array[a, 100] %Y A333262 Cf. A071324, A330786. %K A333262 nonn %O A333262 1,3 %A A333262 _Amiram Eldar_, Mar 13 2020