1. Define a sequence of numbers in the following way:
a[k]=a[k-1]+a[k-2]+a[k-3] for k≥3, s.t. a[0]=1, a[1]=2, a[2]=3, a[3]=6...
*The numbers in brackets will be subscripts for the whole problem
Prove that a[n]≤2^n using complete mathematical induction.
This is what I have so far.
We'll use...