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%I #18 May 02 2015 10:20:14
%S 278,528,582,826,2385,2585,2868,2872,2875,2878,2885,4782,4832,4872,
%T 5278,5328,6872,7238,7258,7268,7582,8232,8266,8275,8278,8284,8522,
%U 8524,8528,8628,8732,8822,23385,23628,23782,23826,25582,25668,25785,25856,26238,26878
%N Numbers n such that the decimal expansions of both n and n^2 have 2 as smallest digit and 8 as largest digit.
%H Felix Fröhlich, <a href="/A257368/b257368.txt">Table of n, a(n) for n = 1..10000</a>
%t fQ[n_] := Block[{d = DigitCount@ n}, Plus @@ Prepend[Take[d, -2], First@ d] == 0 && d[[2]] > 0 && d[[8]] > 0]; Select[Range@ 27000, fQ@ # && fQ[#^2] &] (* _Michael De Vlieger_, Apr 27 2015 *)
%o (PARI) is(n) = vecmin(digits(n))==2 && vecmin(digits(n^2))==2 && vecmax(digits(n))==8 && vecmax(digits(n^2))==8
%Y Cf. A256630, A256631, A256633, A256634, A256708, A256709, A256889, A257123, A257197, A257210, A257211, A256601, A257310.
%K nonn,base
%O 1,1
%A _Felix Fröhlich_, Apr 25 2015
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