Hemachandra Number (Why calling it Febonacci Number ?)

As documented by Donald Knuth in The Art of Computer Programming, this sequence was first described by the Indian mathematicians Gopala and Hemachandra in 1150, who were investigating the possible ways of exactly bin packing items of length 1 and 2. In the West, it was first studied by Leonardo of Pisa, who was also known as Fibonacci (c. 1200), to describe the growth of an idealized rabbit population. The numbers describe the number of pairs in the rabbit population after n months if it is assumed that

* in the first month there is just one new-born pair,
* new-born pairs become fertile from their second month on
* each month every fertile pair begets a new pair, and
* the rabbits never die