%I #14 Sep 08 2022 08:44:57
%S 0,1,2,3,4,5,6,7,8,9,23,43,49,61,100,122,136,148,163,200,221,244,269,
%T 300,305,366,400,481,488,500,600,629,700,800,884,900,1105,1127,1222,
%U 1241,1281,1438,1522,1641,1805,2300,2405,2722,2966,3203,4205,4300,4402
%N Numbers n such that replacing digits d in decimal expansion of n with d^2 yields a square.
%e 2722 = (2)(7)(2)(2) -> (4)(49)(4)(4) = 44944 = 212^2 and square.
%o (Magma) f:=func<n|StringToInteger(&cat[IntegerToString(h): h in Reverse([c^2: c in Intseq(n)])])>; [0] cat [k:k in [1..4500]|IsSquare(f(k))]; // _Marius A. Burtea_, Feb 13 2020
%Y Cf. A000290, A048385, A048387.
%K nonn,base
%O 1,3
%A _Patrick De Geest_, Mar 15 1999