A103618 Number of steps required for n to reach a digit count invariant or cycle loop under the 'Look and Say' function A045918.

10, 12, 11, 12, 8, 10, 10, 10, 10, 10, 9, 11, 10, 11, 7, 9, 9, 9, 9, 9, 6, 10, 0, 9, 6, 6, 6, 6, 6, 6, 8, 11, 9, 10, 6, 8, 8, 8, 8, 8, 9, 7, 6, 6, 7, 8, 9, 9, 9, 9, 10, 9, 6, 8, 8, 7, 9, 10, 10, 10, 12, 9, 6, 8, 9, 9, 7, 10, 12, 12, 13, 9, 6, 8, 9, 10, 10, 7, 12, 13, 14, 9, 6, 8, 9, 10, 12, 12, 7, 13

Offset

1,1

Links

Table of n, a(n) for n=1..90.

Madras Math., Descriptive Numbers: Table of results

Example

a(10)=9 because we have the 9-step chain 10 -> 1011 -> 1031 -> 102113 -> 103112113 -> 10411223 -> 1031221314 -> 1041222314 -> 1031321324 -> 1031223314, the latter being autobiographical, hence invariant. Also, a(40)=9 since we have the digit count iteration 40 -> 1014 -> 102114 -> 10311214 -> 1041121314 -> 1051121324 -> 104122131415 -> 105122132415 -> 104132131425 -> 104122232415 <-> 103142132415, ending in a 2-cycle loop.

Crossrefs

Cf. A005151, A047841, A104785, A104786, A104787, A308781 (duplicate?).

Sequence in context: A284229 A078285 A303151 * A308781 A317180 A187285

Adjacent sequences: A103615 A103616 A103617 * A103619 A103620 A103621

Keyword

nonn,base

Author

Lekraj Beedassy, Mar 25 2005

Extensions

Corrected and extended by Sean A. Irvine, Feb 08 2010

Status

approved