%I #4 May 30 2021 14:15:44
%S 1,4,4,4,13,13,13,13,13,13,13,13,13,40,40,40,40,40,40,40,40,40,40,40,
%T 40,40,40,40,40,40,40,40,40,40,40,40,40,40,40,40,121,121,121,121,121,
%U 121,121,121,121,121,121,121,121,121,121,121,121,121,121,121,121,121,121
%N (3^k - 1)/2 appears 3^(k-1) times, k>0.
%F a(n+1) = 3*a(floor(n/3)) + 1; a(0) = 1.
%t Table[PadRight[{},3^(k-1),(3^k-1)/2],{k,5}]//Flatten (* _Harvey P. Dale_, May 30 2021 *)
%Y Cf. A003462, A007448, A003817.
%K nonn
%O 0,2
%A _Reinhard Zumkeller_, Jul 18 2010
%E Erroneous comment deleted by _Reinhard Zumkeller_, Jul 23 2010