A072217 Consider the Reverse and Add! problem (cf. A001127); of all the n-digit numbers N which eventually reach a palindrome, pick that number N which takes the greatest number of steps to converge (in case of a tie, pick the smallest N); sequence gives number of steps N takes to converge.

2, 24, 23, 21, 55, 64, 96, 96, 98, 109, 149, 149, 188, 186, 201, 197, 236, 232

Offset

1,1

Comments

Since we do not even know if 196 eventually converges (see A006960, A023108) for n >= 3 these values are only conjectures.

Links

Table of n, a(n) for n=1..18.

Jason Doucette, World records

Index entries for sequences related to Reverse and Add!

Crossrefs

Cf. A072216, A072218, A001127, A006960, A023108.

Sequence in context: A290772 A342545 A055535 * A229429 A281139 A052686

Adjacent sequences: A072214 A072215 A072216 * A072218 A072219 A072220

Keyword

nonn,hard,base

Author

N. J. A. Sloane, Jul 05 2002

Extensions

Corrected and extended by Jason Doucette, Mar 29 2005; Oct 09 2005

Status

approved