OFFSET
1,3
EXAMPLE
E.g. 518041 = (5)(1)(8)(0)(4)(1) -> (125)(1)(512)(0)(64)(1) = 12515120641 = 111871^2 and a square.
MATHEMATICA
Select[Range[0, 561*10^4], IntegerQ[Sqrt[FromDigits[Flatten[ IntegerDigits/@ (IntegerDigits[ #]^3)]]]]&] (* Harvey P. Dale, Apr 15 2019 *)
PROG
(PARI) ccd(n) = {if (n==0, return(0)); my(d = digits(n)); my(nd = ""); for (i=1, #d, nd = Str(nd, d[i]^3); ); eval(nd); }
isok(n) = issquare(ccd(n)); \\ Michel Marcus, Oct 19 2016
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Mar 15 1999
EXTENSIONS
Offset corrected by Michel Marcus, Oct 19 2016
STATUS
approved