%I #15 Mar 08 2020 22:57:53
%S 1,10,19,199,19999999999999999999999
%N Alternative version of A006050.
%C This is also the smallest n such that digit sum of n = previous term. - _Dominick Cancilla_, Aug 09 2010
%D H. J. Hindin, The additive persistence of a number, J. Rec. Math., 7 (No. 2, 1974), 134-135.
%H N. J. A. Sloane, <a href="http://neilsloane.com/doc/persistence.html">The persistence of a number</a>, J. Recreational Math., 6 (1973), 97-98.
%F For n > 1, a(n) = 2*10^((a(n-1)-1)/9) - 1.
%t Join[{1},NestList[2*10^((#-1)/9)-1&,10,3]] (* _Harvey P. Dale_, Sep 20 2011 *)
%Y Cf. A003001, A006050.
%K nonn,base,nice
%O 0,2
%A _N. J. A. Sloane_
%E Next term is 1 followed by 2222222222222222222222 9s.