Numbers n such that n and floor[n/3] are both squares; i.e. squares which remain squares when written in base 3 and last digit is removed.
0, 1, 4, 49, 676, 9409, 131044, 1825201, 25421764, 354079489, 4931691076
1 seqfan posts
Thu Apr 23 21:29:22 CEST 2009 [seqfan] Re: Offsets for Recurrence Sequences