A085309 Initial values providing nontrivial cyclic attractor when function defined in A085307 is iterated.

213, 323, 639, 713

Offset: 1

Author

Labos Elemer, Jun 27 2003

Keywords

• base
• nonn

Examples

			n=213 gives {213,713,3123,3473,15123,713},
n=323 gives {323,1917,713,3123,3473,15123,713},
n=639 gives {639,713,3123,3473,15123,713}.
		

Crossrefs

Cf. A084317-A084319, A085307, A085308, A085309.

Formula

Algorithm: 1# factorize n; 2# arrange prime-factors by decreasing size; 3# concatenate prime factors and interpret the result as decimal number.Iterate 1#, 2#, 3#.