OFFSET
2,1
COMMENTS
a(n) = smallest square whose base n representation contains only 0's and 1's.
FORMULA
a(1) = 4, a(k^2-1) = a(k^2) = k^2, a(n) = n^2 otherwise. - Charlie Neder, Mar 08 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Nov 19 2002
EXTENSIONS
Corrected and extended by Ray Chandler, Sep 04 2003
STATUS
approved