09.12.2012 Views

Concrete mathematics : a foundation for computer science

Concrete mathematics : a foundation for computer science

Concrete mathematics : a foundation for computer science

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

496 ANSWERS TO EXERCISES<br />

the circle passes through as many cells as there are crossing points, namely<br />

8n - 4 = 8r. (The same <strong>for</strong>mula gives the number of cells at the edge of the<br />

board.) (b) f(n, k) =41-j.<br />

It follows from (a) and (b) that<br />

The task of obtaining more precise estimates of this sum is a famous problem<br />

in number theory, investigated by Gauss and many others; see Dickson [65,<br />

volume 2, chapter 61.<br />

3.34 (a) Let n = [lgn] . We can add 2”’ - n terms to simplify the calculations<br />

at the boundary:<br />

f(n)+(2m-n)m = c[lgk] = xj[j=[lgk]][l

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!