Evaluate the sum of reciprocals of double factorial of even nonnegative integers.

**x^3 + y^3 + z^3 = w^3**.

The smallest set of positive integers x,y,z,w qualifying as a solution of the bolded equation above is: **
3,4,5,6 **

a.Find some other sets of distinct integers, not necessarily positive.

b. Provide some comments on "The sum of 3 cubes is a cube" equation.

One Martian, one Venusian and one Human reside on Pluto.

One day they make the following conversation:

Martian: I have spent 1/12 of my life in Pluto.

Human: I also have.

Venusian: Me too.

Martian: But Venusian and I have spent much more time here than you, Human.

Human: However Venusian and I are of the same age.

Venusian: I have lived 300 Earth years.

Martian: Venusian and I have been on Pluto for the last 13 years.

It is known that Human and Martian together have lived for 104 Earth years.

Find their respective ages.

HINT:
The numbers are not necessarily expressed in base 10 .

Source: 1971 IMO longlisted problem.

How many ones are used in writing all of the numbers from 0 to 2018 (inclusive) in binary form?