Comments on: Project Euler problem 28 http://duncan99.wordpress.com/2009/02/01/project-euler-problem-28/ Just another WordPress.com weblog Fri, 01 Mar 2013 18:26:06 +0000 hourly 1 http://wordpress.com/ By: Daniel Robert Webb http://duncan99.wordpress.com/2009/02/01/project-euler-problem-28/#comment-480 Tue, 24 Apr 2012 04:31:50 +0000 http://duncan99.wordpress.com/?p=915#comment-480 Please disregard my post. I realize my error. Garbage in, Garbage out!

]]> By: Daniel Robert Webb http://duncan99.wordpress.com/2009/02/01/project-euler-problem-28/#comment-479 Tue, 24 Apr 2012 03:16:17 +0000 http://duncan99.wordpress.com/?p=915#comment-479 This 3 years after the last post so I don’t know if any one is following this. With to above formula, I now have two ways to come up with the same answer that gets rejected. Please allow me to post both python programs.

S=1
for i in range(3,10002,2):
t=i*i
t2 = t-(i-1)
t3 = t2-(i-1)
t4 = t3-(i-1)
S = S+t+t2+t3+t4

print S

# and
n=10001
S = (4*n**3+3*n**2+8*n-9)/6
print S
###########

And the answer I get is: 666916710001

Any Ideas?

]]> By: Project Euler problem 58 « Duncan’s blog http://duncan99.wordpress.com/2009/02/01/project-euler-problem-28/#comment-304 Sun, 13 Dec 2009 09:08:22 +0000 http://duncan99.wordpress.com/?p=915#comment-304 [...] problem has some similarities to problem 28. In that case the spiral went clockwise; this one it goes anti-clockwise. For our purposes [...]

]]> By: ggse http://duncan99.wordpress.com/2009/02/01/project-euler-problem-28/#comment-281 Wed, 15 Jul 2009 10:57:19 +0000 http://duncan99.wordpress.com/?p=915#comment-281 The sum is also given by a formula : for a n by n spiral, S = (4*n^3+3*n^2+8*n-9)/6.

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