

A066144


In base 2: n sets a new record for the number of 'Reverse and Add' steps needed to reach a palindrome starting with n.


5



0, 2, 11, 19, 20, 74, 398, 779, 1062, 2329, 4189, 4280, 11278, 19962, 98318, 135137, 1051360, 1592930
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OFFSET

0,2


COMMENTS

The analog of A065198 in base 2. Integers like 22, for which a palindrome is never reached (cf. A066059), are of course disregarded. A066145 gives the corresponding records.


LINKS

Table of n, a(n) for n=0..17.
Index entries for sequences related to Reverse and Add!


EXAMPLE

Starting with 74, 11 'Reverse and Add' steps are needed to reach a palindrome; starting with n < 74, less (at most 5) steps are needed.


MATHEMATICA

limit = 10^4; (* Assumes that there is no palindrome if none is found before "limit" iterations *)
best = 1; Select[Range[0, 100000], (np = #; i = 0;
While[np != IntegerReverse[np, 2] && i < limit,
np = np + IntegerReverse[np, 2]; i++];
If[i >= limit, False, If[i > best, best = i; True]]) &] (* Robert Price, Oct 14 2019 *)


CROSSREFS

Cf. A065198, A062130, A066057, A066058, A066059, A066145.
Sequence in context: A030551 A121848 A074926 * A102343 A023173 A018443
Adjacent sequences: A066141 A066142 A066143 * A066145 A066146 A066147


KEYWORD

base,more,nonn,changed


AUTHOR

Klaus Brockhaus, Dec 08 2001


STATUS

approved



