A124918 - OEIS

%I #12 Mar 15 2024 07:26:40

%S 0,2,9,3,0,10,4,1,17,14,8,5,2,21,18,37,15,12,9,28,6,25,3,22,0,19,38,

%T 16,35,13,54,32,10,29,7,48,26,4,45,23,1,42,20,61,39,80,17,58,36,77,14,

%U 55,33,74,11,52,30,134,8,49,153,27,68,5,46,150,24,65,2,43,147,21,125,62

%N a(n) = least integer k >= 0 such that n = floor((5^j)/(3^k)) for some integer j >= 0.

%C Every nonnegative integer occurs infinitely many times. The j-sequence is A124910.

%H Robert Israel, <a href="/A124918/b124918.txt">Table of n, a(n) for n = 1..10000</a>

%e 1 = floor(5^0 / 3^0),

%e 2 = floor(5^2 / 3^2),

%e 3 = floor(5^7 / 3^9),

%e 4 = floor(5^3 / 3^3), ...,

%e so j-sequence = (0,2,7,3,...); k-sequence = (0,2,9,3,...).

%p N:= 100: # for a(1) .. a(N)

%p V:=Vector(N,-1): count:= 0:

%p for j from 0 while count < N do

%p   x:= 5^j;

%p   k0:= max(0,floor(log[3](x/N)));

%p   x:= x/3^(k0-1);

%p   for k from k0 do

%p     x:= x/3;

%p     if x < 1 then break fi;

%p     m:= floor(x);

%p     if m <= N and V[m] = -1 then V[m]:= k; count:= count+1 fi

%p od od:

%p convert(V,list); # _Robert Israel_, Mar 08 2024

%Y Cf. A124910.

%K nonn

%O 1,2

%A _Clark Kimberling_, Nov 13 2006