This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A048386 #14 Sep 08 2022 08:44:57 %S A048386 0,1,2,3,4,5,6,7,8,9,23,43,49,61,100,122,136,148,163,200,221,244,269, %T A048386 300,305,366,400,481,488,500,600,629,700,800,884,900,1105,1127,1222, %U A048386 1241,1281,1438,1522,1641,1805,2300,2405,2722,2966,3203,4205,4300,4402 %N A048386 Numbers n such that replacing digits d in decimal expansion of n with d^2 yields a square. %e A048386 2722 = (2)(7)(2)(2) -> (4)(49)(4)(4) = 44944 = 212^2 and square. %o A048386 (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 A048386 Cf. A000290, A048385, A048387. %K A048386 nonn,base %O A048386 1,3 %A A048386 _Patrick De Geest_, Mar 15 1999