Brute force Strategy Example #2

[user5760]

I’m not understanding why to get S7 you can add S4 and S3?

To solve for S7, I did S(7/2) + S(7/2) + 1. Hence I took the smallest integer greater than or equal to x to be 4 and the greatest integer smaller than or equal to x to be 3. Hence 4+3+1=8

I thought that in a sequence notation when there is Sn or An, you have to substitute the value of n for each time the subscript appears. Is there a sequence notation rule in which Sn + Sn = S(n+n)? Why am I wrong?

[Leaderboard]

@user5760

S7, I did S(7/2) + S(7/2) + 1.

Yes, but then you somehow assumed that S_n = n?

[user5760]

Thanks! I understood my mistake now. The sequence notation is a recurrence relation, not the other. Indeed, I then incorrectly assumed that Sn = n.