A sequence with the recurrence f(n)=3*f(n-1)+f(n-2) starts with two 1-digit numbers. The sequence contains the 8-digit number ABCDAECD. A≠0, and A, B, C, D, and E are not necessarily distinct. Find all possible values of ABCDAECD.
In Charlie's list I saw this entry:2 5 28572857
This has B=E. It is a unique solution if we had been asked for a number of the form ABCDABCD. Looking for a number of this form may be a reasonable problem, as we could take advantage of searching for multiples of 10001.