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%I #13 May 11 2020 06:39:32
%S 1,2,4,8,16,122,442,884,1768,17522,150442,1088420,17684200,175284200,
%T 1750844200,17508842000,177508420000,1755084200000,17510842000000,
%U 175084220000000,1750844200000000,17508842000000000,177508420000000000,1755084200000000000
%N Numbers produced by iteratively sorting the digits of the last number from largest to smallest in base 10 and then doubling, starting with the number 1.
%C It appears that the first 8 digits begin to cycle in a period of 6 while adding one zero every iteration.
%t a[1] = 1; a[n_] := a[n] = 2 FromDigits@ Reverse@ Sort@ IntegerDigits@ a[n-1]; Array[a, 24] (* _Giovanni Resta_, Apr 15 2020 *)
%o (PARI) lista(nn) = {my(a=1); print1(a, ", "); for (n=2, nn, a = 2*fromdigits(vecsort(digits(a),,4)); print1(a, ", "););} \\ _Michel Marcus_, Apr 16 2020
%Y Cf. A004000, A057615, A095197.
%K nonn,base
%O 1,2
%A _Ethan Hulinsky_, Mar 14 2020