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 A257485 #11 Dec 06 2018 12:35:14
%S A257485 927,962,982,2293,2393,2593,2693,2792,2923,2927,2932,2937,2964,2973,
%T A257485 2977,2982,2983,4792,4923,4927,5692,6292,6923,6925,6927,7923,7924,
%U A257485 7927,8792,8925,9232,9233,9267,9268,9273,9286,9287,9288,9325,9326,9327,9342,9423,9427
%N A257485 Numbers n such that the decimal expansions of both n and n^2 have 2 as smallest digit and 9 as largest digit.
%H A257485 Felix Fröhlich, <a href="/A257485/b257485.txt">Table of n, a(n) for n = 1..10000</a>
%t A257485 fQ[n_] := Block[{d = DigitCount@ n}, Plus @@ Join[First@ d, Last@ d] == 0 && d[[2]] > 0 && d[[9]] > 0]; Select[Range@ 10000, fQ@ # && fQ[#^2] &] (* _Michael De Vlieger_, Apr 27 2015 *)
%t A257485 s2l9Q[n_]:=Max[IntegerDigits[n]]==9&&Min[IntegerDigits[n]]==2; Select[ Range[ 10000],AllTrue[{#,#^2},s2l9Q]&] (* _Harvey P. Dale_, Dec 06 2018 *)
%o A257485 (PARI) is(n) = vecmin(digits(n))==2 && vecmin(digits(n^2))==2 && vecmax(digits(n))==9 && vecmax(digits(n^2))==9
%Y A257485 Cf. A256630, A256631, A256633, A256634, A256708, A256709, A256889, A257197, A257210, A257211, A256601, A257310, A249915, A257123, A257368.
%K A257485 nonn,base
%O A257485 1,1
%A A257485 _Felix Fröhlich_, Apr 26 2015