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Add and Reverse: a(n) = the reversal of (a(n-1)+d), case a(1)=1 and d=4.
5

%I #33 Mar 16 2022 20:00:21

%S 1,5,9,31,53,75,97,101,501,505,905,909,319,323,723,727,137,141,541,

%T 545,945,949,359,363,763,767,177,181,581,585,985,989,399,304,803,708,

%U 217,122,621,526,35,93,79,38,24,82,68,27,13,71,57,16,2,6,1,5,9,31,53,75,97

%N Add and Reverse: a(n) = the reversal of (a(n-1)+d), case a(1)=1 and d=4.

%C Cycle of length 54. [Corrected by _N. J. A. Sloane_, Aug 02 2009]

%H Michael De Vlieger, <a href="/A119031/b119031.txt">Table of n, a(n) for n = 1..10000</a>

%t Nest[Append[#, IntegerReverse[#[[-1]] + 4]] &, {1}, 60] (* _Michael De Vlieger_, Mar 14 2021 *)

%o (Python)

%o def A119031(N=60, a=1, d=4): # optional args: # terms, initial value, increment

%o for _ in range(N): yield a; a=int(str(a+d)[::-1])

%o list(A119031()) # _M. F. Hasler_, Mar 15 2022

%o (PARI) a=6; A119031=vector(60,i,a=fromdigits(Vecrev(digits(a+4)))) \\ _M. F. Hasler_, Mar 15 2022

%Y All of A003608, A016081, A016082 (and possibly others) eventually reach the trajectory of 1 shown in A119031. Cf. A055198.

%Y Cf. A016081 (case a(1)=3).

%K nonn,base

%O 1,2

%A _Zak Seidov_, May 09 2006