OFFSET
1,2
EXAMPLE
28113 = (2)(8)(1)(1)(3) -> (3)(19)(2)(2)(5) = 319225 = 565^2.
MATHEMATICA
Select[Range[0, 650000], IntegerQ[Sqrt[FromDigits[Flatten[IntegerDigits/@ (If[#==0, 1, Prime[#]]&/@IntegerDigits[#])]]]]&] (* Harvey P. Dale, Mar 27 2011 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Mar 15 1999
EXTENSIONS
Definition edited and offset corrected by M. F. Hasler, Oct 11 2019
STATUS
approved