A124911 a(n) = least integer j>=0 such that n = floor((5^j)/(2^k)) for some integer k>=0.

0, 1, 2, 4, 1, 2, 3, 16, 4, 20, 8, 2, 18, 9, 3, 22, 16, 10, 4, 26, 20, 14, 8, 5, 2, 24, 18, 15, 9, 6, 3, 28, 22, 19, 16, 13, 10, 7, 4, 29, 26, 23, 20, 17, 14, 11, 8, 5, 33, 30, 27, 24, 52, 21, 18, 15, 43, 12, 9, 37, 6, 3, 31, 28, 56, 25, 22, 50, 19, 47, 16, 13, 41, 10, 38, 7, 35, 4, 60

Offset

1,3

Comments

The k-sequence is A124919.

Links

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

Example

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

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[2](x/N)));
  x:= x/2^(k0-1);
  for k from k0 do
    x:= x/2;
    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 14 2024

Crossrefs

Cf. A124919.

Sequence in context: A269065 A206475 A227184 * A132954 A069705 A106645

Adjacent sequences: A124908 A124909 A124910 * A124912 A124913 A124914

Keyword

nonn

Author

Clark Kimberling, Nov 13 2006

Status

approved