Sometimes I wish I could share solutions to PE problems. They’re so great! I totally enjoyed every bit of this week’s puzzle. At first you don’t know where to start, it seems so complicated and then you just immense yourself in the pleasure of thinking and bit by bit everything becomes crystal clear so that in the end you can say “Hey! It was easy” π

– A SierpiΕski graph of order-1 (S

_{1}) is an equilateral triangle.

– S_{n+1}is obtained from S_{n}by positioning three copies of S_{n}so that every pair of copies has one common corner.Let C(n) be the number of cycles that pass exactly once through all the vertices of S

_{n}.

For example, C(3) = 8 because eight such cycles can be drawn on S_{3}, as shown below:It can also be verified that :

C(1) = C(2) = 1

C(5) = 71328803586048

C(10 000) mod 10^{8}= 37652224

C(10 000) mod 13^{8}= 617720485Find C(C(C(10 000))) mod 13

^{8}.

I felt the same way when I first read this problem but I was surprised to find a very simple and elegant pattern. This was the first problem where I was able to submit a solution in the top 100.

You seem to be getting all of the latest euler problems. I’m wondering what’s your background?

http://us.linkedin.com/pub/stanislaw-adaszewski/3/800/448

But even more importantly, I finally got interested in maths after trying PE π That’s why I’m not going to stop solving those challenges π

What is Your background then? π

udalo mi sie wyprowadzic wzor ogolny, ale liczby sΔ mega, mecze sie z tym od paru dni, gratuluje π

Please help me with this problem. I derived nice formulas for C(n), but i dont quite get it how to calculate C(C(C(10000))) mod 13^8 from there.

Think PE. It’s pretty obvious that this problem would be unsolvable if C(n) wasn’t… what? π

what? =

What does distinct mean here?

Opps wrong problem