OFFSET
1,1
COMMENTS
Probably there are no other terms. No other terms up to 10^40.
EXAMPLE
The squares of 5, 235, 72335 are 25, 55225, 5232352225.
MATHEMATICA
Flatten[Table[Select[FromDigits/@Tuples[{2, 3, 5, 7}, n], AllTrue[ IntegerDigits[ #^2], PrimeQ]&], {n, 5}]] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 16 2014 *)
CROSSREFS
KEYWORD
nonn,bref,base
AUTHOR
Zak Seidov, Dec 17 2008
EXTENSIONS
Edited by David Wilson and N. J. A. Sloane, Jan 25 2009
STATUS
approved