A124910 a(n) = least integer j >= 0 such that n = floor((5^j)/(3^k)) for some integer k >= 0.

0, 2, 7, 3, 1, 8, 4, 2, 13, 11, 7, 5, 3, 16, 14, 27, 12, 10, 8, 21, 6, 19, 4, 17, 2, 15, 28, 13, 26, 11, 39, 24, 9, 22, 7, 35, 20, 5, 33, 18, 3, 31, 16, 44, 29, 57, 14, 42, 27, 55, 12, 40, 25, 53, 10, 38, 23, 94, 8, 36, 107, 21, 49, 6, 34, 105, 19, 47, 4, 32, 103, 17, 88, 45, 116, 30

Offset

1,2

Comments

The k-sequence is A124918.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

1 = floor(5^0 / 3^0),
2 = floor(5^2 / 3^2),
3 = floor(5^7 / 3^9),
4 = floor(5^3 / 3^3), ...,
so j-sequence = (0,2,7,3,...); k-sequence = (0,2,9,3,...).

Maple

N:= 100: # for a(1) .. a(N)
V:=Vector(N, -1): count:= 0:
for j from 0 while count < N do
  x:= 5^j;
  k0:= max(0, floor(log[3](x/N)));
  x:= x/3^(k0-1);
  for k from k0 do
    x:= x/3;
    if x < 1 then break fi;
    m:= floor(x);
    if m <= N and V[m] = -1 then V[m]:= j; count:= count+1 fi
od od:
convert(V, list); # Robert Israel, Mar 08 2024

Crossrefs

Cf. A124918.

Sequence in context: A356381 A197281 A019703 * A303954 A090388 A361694

Adjacent sequences: A124907 A124908 A124909 * A124911 A124912 A124913

Keyword

nonn

Author

Clark Kimberling, Nov 13 2006, corrected Nov 13 2006

Status

approved