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A066145 In base 2, records for the number of 'Reverse and Add' steps needed to reach a palindrome. 5

%I #22 May 16 2022 16:20:34

%S 0,1,2,4,5,11,21,32,37,46,48,49,53,89,99,142,147,273,297,345,515,550,

%T 573

%N In base 2, records for the number of 'Reverse and Add' steps needed to reach a palindrome.

%C The analog of A065199 in base 2. A066144 gives the corresponding starting points.

%C Terms a(19..22) obtained by assuming that a(n+1) <= a(n) + 300. - _A.H.M. Smeets_, Apr 30 2022

%H <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a>

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

%t limit = 10^3; (* Assumes that there is no palindrome if none is found before "limit" iterations *)

%t best = -1; lst = {};

%t For[n = 0, n <= 10000, n++,

%t np = n; i = 0;

%t While[np != IntegerReverse[np, 2] && i < limit,

%t np = np + IntegerReverse[np, 2]; i++];

%t If[i < limit && i > best, best = i; AppendTo[lst, i]]]; lst (* _Robert Price_, Oct 14 2019 *)

%Y Record values in base b: A077407 (b=3), A075687 (b=4), A306600 (b=8), A065199 (b=10), A348572 (Zeckendorf).

%Y Cf. A062130, A066057, A066058, A066059, A066144.

%K base,more,nonn

%O 1,3

%A _Klaus Brockhaus_, Dec 08 2001

%E Offset corrected and a(19)-a(23) by _A.H.M. Smeets_, Apr 30 2022

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Last modified March 29 04:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)