There really is no single "obvious" choice here...
Possibly the sequence is periodic, with seven copies of -1 followed by six copies of 0, or perhaps seven -1s and seven 0s. Or maybe seven -1s, followed by six 0s, then five 1s, and so on, but after a certain point it would seem we have to have negative copies of a number, which is meaningless.
Or maybe it's not periodic, and every seventh value in the sequence is incremented by 1? Who knows?
I'll go ahead and assume the latter case, that the sequence is not periodic, since that's technically somewhat easier to manage. We can assign the following rule to the

-th term in the sequence:


for

.
So the generating function for this sequence might be

As to what is meant by "closed form", I'm not sure. Would this answer be acceptable? Or do you need to find a possibly more tractable form for the coefficient not in terms of the floor function?
Answer:
$36.8
Step-by-step explanation:
Answer:
slope is change in rise(y) over change in run (x), change in y here is 36 and change in x is 2, slope is 36/2=18
Answer:
16
Step-by-step explanation:
perimeter of B = 21
divide by 3 to get each side: 21/3 = 7 = Y
perimeter of hexagon is 50. subtract 2Y: 50 - 14 = 36
divide 36 by 4 to find X = 9
add X + Y