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

4899999987, 4989999897, 4999889997, 4999997889, 5889998997, 5889999969, 5898989997, 5898998988, 5899899789, 5899979979, 5899987998, 5899989699, 5899996989, 5979999879, 5988899997, 5988998898, 5989889979, 5989897998

Offset: 1

Author

Labos Elemer, Jun 05 2002

Keywords

• nonn
• base

Examples

			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.
		

Links

• Sean A. Irvine, Table of n, a(n) for n = 1..1000

Crossrefs

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