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A081848 Number of numbers whose base-3/2 expansion (see A024629) has n digits.

%I A081848 #48 Sep 21 2022 01:42:21
%S A081848 3,3,3,6,9,12,18,27,42,63,93,141,210,315,474,711,1065,1599,2397,3597,
%T A081848 5394,8091,12138,18207,27309,40965,61446,92169,138255,207381,311073,
%U A081848 466608,699912,1049868,1574802,2362203,3543306,5314959,7972437,11958657
%N A081848 Number of numbers whose base-3/2 expansion (see A024629) has n digits.
%C A081848 Run lengths in A246435. - _Reinhard Zumkeller_, Sep 05 2014
%H A081848 Reinhard Zumkeller, <a href="/A081848/b081848.txt">Table of n, a(n) for n = 1..1000</a>
%H A081848 B. Chen, R. Chen, J. Guo, S. Lee et al., <a href="http://arxiv.org/abs/1808.04304">On Base 3/2 and its sequences</a>, arXiv:1808.04304 [math.NT], 2018.
%H A081848 J. S. Tanton, <a href="https://web.archive.org/web/20110108124656/http://www.themathcircle.org/researchproblems.php">A collection of research problems</a>.
%F A081848 For n > 1, a(n) = A070885(n+1) - A070885(n). - _Tom Edgar_, Jun 25 2014
%F A081848 a(n) = 3*A073941(n). - _Tom Edgar_, Jul 21 2014
%e A081848 a(1) = 3 because 0, 1 and 2 each have 1 digit.
%o A081848 (Haskell)
%o A081848 a081848 n = a081848_list !! (n-1)
%o A081848 a081848_list = 3 : tail (zipWith (-) (tail a070885_list) a070885_list)
%o A081848 -- _Reinhard Zumkeller_, Sep 05 2014
%o A081848 (Python)
%o A081848 from itertools import islice
%o A081848 def A081848_gen(): # generator of terms
%o A081848     yield (a:=3)
%o A081848     while True:
%o A081848         yield (b:=(a+1>>1)+(a&1))
%o A081848         a += b
%o A081848 A081848_list = list(islice(A081848_gen(),70)) # _Chai Wah Wu_, Sep 20 2022
%Y A081848 Cf. A024629, A070885, A073941, A246435.
%K A081848 easy,nonn,base
%O A081848 1,1
%A A081848 _N. J. A. Sloane_, Apr 13 2003
%E A081848 More terms from _David Wasserman_, Jun 28 2004
%E A081848 Edited by _Charles R Greathouse IV_, Aug 02 2010