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 A355300 #11 Jul 02 2022 14:44:48 %S A355300 0,1,1,2,1,2,2,3,1,2,1,2,2,3,2,2,1,3,2,4,1,1,3,3,2,2,3,4,3,4,2,4,1,3, %T A355300 2,2,2,2,3,3,1,3,1,2,2,5,2,3,2,6,2,2,2,2,2,2,2,4,3,2,2,2,3,2,1,4,3,3, %U A355300 3,3,2,3,3,3,3,3,4,3,4,4,1,3,2,4,1,3,2,4,3,3,2,2,2 %N A355300 a(0) = 0; for n >= 1, a(n) = a(A007088(n) mod n) + 1. %C A355300 Number of steps needed to reach zero when starting from k = n and repeatedly applying the map that replaces k by A007088(k) mod k. For a(n) = 1 see A032533. %C A355300 a(95980631) = 26. - _Charles R Greathouse IV_, Jun 30 2022 %e A355300 n = 12, a(12) = a(1100 mod 12) + 1 = a(8) + 1 = a(1000 mod 8) + 2 = a(0) + 2 = 2. %t A355300 a[n_] := a[n] = a[Mod[FromDigits[IntegerDigits[n, 2]], n]] + 1; a[0] = 0; Array[a, 100, 0] (* _Amiram Eldar_, Jun 27 2022 *) %o A355300 (PARI) f(n) = fromdigits(binary(n), 10); \\ A007088 %o A355300 a(n) = if (n, a(f(n) % n)+1, 0); \\ _Michel Marcus_, Jun 27 2022 %Y A355300 Cf. A007088, A032533. %K A355300 nonn,base %O A355300 0,4 %A A355300 _Ctibor O. Zizka_, Jun 27 2022