The Easy Number is in fact the Automorphic Number. And a number is a Automorphic Number when and only when it is the suffix of another Automorphic Number. So, I download a program to make the Automorphic Number of 2000 dights. And...

Edited by author 14.03.2009 22:51

Edited by author 14.03.2009 22:51

Edited by author 14.03.2009 22:51

It is evident.
But how to implement this without long arithmetic.
My solution uses Java.BigInteger and reccurence:
k^2*10^2*L+k*(2*A-1)*10^L+Z*10^L=Z1*10^L1;
where A*A-A=Z*10^L
and A1=k*10^L+A- new value where
A1*A1-A1=Z1*10^L1, L1>=L+1

Preculc works nice :)

well, you win,,,,,