cp's OEIS Frontend

A134025 Numbers for which the balanced ternary representation is the same length as the ternary representation.

%I A134025 #16 Dec 15 2015 19:05:32
%S A134025 0,1,3,4,9,10,11,12,13,27,28,29,30,31,32,33,34,35,36,37,38,39,40,81,
%T A134025 82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,
%U A134025 103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121
%N A134025 Numbers for which the balanced ternary representation is the same length as the ternary representation.
%C A134025 A003462 is a subsequence; A171960(a(n)) >= a(n). - _Reinhard Zumkeller_, Jan 20 2010
%H A134025 Robert Israel, <a href="/A134025/b134025.txt">Table of n, a(n) for n = 0..10000</a>
%F A134025 a(n) = f(n,0,0) with f(n,m,k) = if n=0 then k else if k<(3^(m+1)-1)/2 then f(n-1,m,k+1) else f(n-1,m+1,3^(m+1)).
%F A134025 A134021(a(n)) = A081604(a(n)).
%F A134025 G.f.: x/(1-x)^2 + (1-x)^(-1)*Sum_{j>=1} ((3^j-1)/2) * x^(3/4 + 3^j/2 + j/2). - _Robert Israel_, Dec 14 2015
%p A134025 0,seq($3^(d-1)..floor(3^d/2), d=0..5); # _Robert Israel_, Dec 14 2015
%t A134025 f[n_, m_, k_] := If[n == 0, k, If[k < (3^(m + 1) - 1)/2, f[n - 1, m, k + 1], f[n - 1, m + 1, 3^(m + 1)]]]; Table[f[n, 0, 0], {n, 0, 63}] (* _L. Edson Jeffery_, Dec 10 2015 *)
%Y A134025 Complement of A134026.
%K A134025 nonn,base
%O A134025 0,3
%A A134025 _Reinhard Zumkeller_, Oct 19 2007