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A257368
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Numbers n such that the decimal expansions of both n and n^2 have 2 as smallest digit and 8 as largest digit.
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10
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278, 528, 582, 826, 2385, 2585, 2868, 2872, 2875, 2878, 2885, 4782, 4832, 4872, 5278, 5328, 6872, 7238, 7258, 7268, 7582, 8232, 8266, 8275, 8278, 8284, 8522, 8524, 8528, 8628, 8732, 8822, 23385, 23628, 23782, 23826, 25582, 25668, 25785, 25856, 26238, 26878
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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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 *)
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PROG
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(PARI) is(n) = vecmin(digits(n))==2 && vecmin(digits(n^2))==2 && vecmax(digits(n))==8 && vecmax(digits(n^2))==8
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CROSSREFS
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Cf. A256630, A256631, A256633, A256634, A256708, A256709, A256889, A257123, A257197, A257210, A257211, A256601, A257310.
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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