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%I #17 Jan 08 2024 10:56:18
%S 20,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,
%T 7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,
%U 3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10
%N Start with 20 and repeatedly reverse the digits and add 1 to get the next term.
%C After 1 step enters a cycle of length 9.
%H N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki.
%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,1).
%e After a(9) = 10 we get a(10) = (reversed digits of a(9)) + 1 = 01 + 1 = 2. - _David A. Corneth_, Jan 08 2024
%t PadRight[{20},100,Range[2,10]] (* _Paolo Xausa_, Jan 08 2024 *)
%o (PARI) a(n) = if(n == 1, return(20)); return(((n-1)%9) + 2) \\ _David A. Corneth_, Jan 08 2024
%Y Cf. A118551.
%Y Essentially the same as A117230.
%K nonn,easy,base
%O 1,1
%A Luc Stevens (lms022(AT)yahoo.com), May 14 2006
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