OFFSET
0,3
COMMENTS
The reverse of every element in the list is also in the list.
Concatenated coefficients of polynomial squares where all coefficients in the square are 0, 1, or 2. - Franklin T. Adams-Watters, Mar 12 2006
EXAMPLE
10100^2 = 102010000 is in the list but 10101^2 = 102030201 (if working in bases >=4) or = 102100201 (if working in base 3) is not.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Henry Bottomley, Dec 07 2001
STATUS
approved