[seqfan] Re: The last digit "d" of a(n) is present in a(n+1+d) --END

Edwin Clark eclark at math.usf.edu
Tue Feb 3 07:29:41 CET 2009

On Mon, 2 Feb 2009, David Wilson wrote:

> I usually like to stay away from "candy sequences" (pleasant to taste but
> bad for you in excess), however,
> a(1) = 0
> a(n+1) = smallest unseen square number sharing no digit with a(n).
> Is this sequence finite?

Candy sequence, yes. But interesting. I can find up to a(1202) = 1075369
To go farther I need a square not in the list:
    4, 484, 28224, 228484, 8282884
whose digits are a subset of {4,2,8}. If my calculations are correct there 
are none with less than 15 digits. But surely there are more such squares.

More information about the SeqFan mailing list