For the sequence given recursively by ak = 2ak-1 - 3 for k > 2, where a1 = 4, someone has guessed a closed form and used the predicate r(n) for the statement "an = 2^n-1 +3." an = 23. oro s (a) are r(1), r(2), r(3), and r(4) true?

True

Step-by-step explanation:

Given that recurrence formula is

and

From this we can find

Let us check now R's for these numbers

R(1) is trivially true

We find that these matches with a values we found using recurrence formula

Hence we can say that R(1), R(2), R(3), and R(4) are true

the correct answer is 5 6 and 7