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A072018 Numbers k for which gcd(k, reverse(k)) = 243 = 3^5. 2

%I

%S 4899999987,4989999897,4999889997,4999997889,5889998997,5889999969,

%T 5898989997,5898998988,5899899789,5899979979,5899987998,5899989699,

%U 5899996989,5979999879,5988899997,5988998898,5989889979,5989897998

%N Numbers k for which gcd(k, reverse(k)) = 243 = 3^5.

%e k = 4899999987 = 3*3*3*3*3*157*128437 and reverse(k) = 78999999984 = 2*2*2*2*3*3*3*3*3*3*2031893, gcd = 243. Numerous but not all solutions are obtained by inserting strings of 9's between digits of A071016. Further such regular transformations exist.

%Y Cf. A004086, A055483, A069554, A071686, A072005, A072016.

%K nonn,base

%O 1,1

%A _Labos Elemer_, Jun 05 2002

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Last modified May 12 11:51 EDT 2021. Contains 343821 sequences. (Running on oeis4.)