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%I #18 Jun 29 2016 00:20:44
%S 0,1,2,2,3,3,4,4,5,5,5,5,6,6,6,6,7,7,7,7,8,8,8,8,9,9,10,10,10,10,11,
%T 11,11,11,12,12,12,12,13,13,13,13,14,14,14,14,14,14,15,15,15,15,16,16,
%U 16,16,17,17,17,17,18,18,18,18,18,18,19,19,19,19,19,19
%N Number of steps to reach 0 starting with n and using the iterated process: x -> x - (sum of digits in factorial expansion of x).
%C See A007623 for the factorial number system representation.
%H A. Karttunen, <a href="/A219652/b219652.txt">Table of n, a(n) for n = 0..10080</a>
%F a(0)=0; for n>0, a(n) = 1 + a(A219651(n)).
%t nn = 72; m = 1; While[Factorial@ m < nn, m++]; m; Table[Length@ NestWhileList[# - Total@ IntegerDigits[#, MixedRadix[Reverse@ Range[2, m]]] &, n, # > 0 &] - 1, {n, 0, nn}] (* _Michael De Vlieger_, Jun 27 2016, Version 10.2 *)
%o (Scheme with memoization macro definec): (definec (A219652 n) (if (zero? n) n (+ 1 (A219652 (A219651 n)))))
%Y Analogous sequence for binary system: A071542, for Zeckendorf expansion: A219642. Cf. A007623, A034968, A219650, A219651, A219653-A219655, A219659, A219661, A219666.
%K nonn,base
%O 0,3
%A _Antti Karttunen_, Nov 25 2012
%E Erroneous description corrected by _Antti Karttunen_, Dec 03 2012