|
%I #11 Apr 17 2015 15:31:56
%S 60,160,460,506,560,600,601,602,605,660,1006,1016,1060,1160,1460,1560,
%T 1600,1601,1602,1620,2006,2016,2060,2160,2460,2560,3606,4506,4600,
%U 4605,4650,5006,5016,5060,5160,5506,5600,5605,5660,6000,6001,6002,6005,6010,6020
%N Numbers n such that the decimal expansions of both n and n^2 have 0 as smallest digit and 6 as largest digit.
%H Felix Fröhlich, <a href="/A256633/b256633.txt">Table of n, a(n) for n = 1..10000</a>
%t fQ[n_] := Block[{c = DigitCount@ n}, And[Plus @@ Take[c, {7, 9}] == 0, c[[6]] > 0, c[[10]] > 0]]; Select[Range@ 6400, fQ@ # && fQ[#^2] &] (* _Michael De Vlieger_, Apr 12 2015 *)
%o (PARI) is(n) = vecmin(digits(n))==0 && vecmin(digits(n^2))==0 && vecmax(digits(n))==6 && vecmax(digits(n^2))==6
%Y Cf. A256630, A256631, A256634, A256708, A256709, A256889, A257085.
%K nonn,base
%O 1,1
%A _Felix Fröhlich_, Apr 05 2015
|
