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A256634 Numbers n such that the decimal expansions of both n and n^2 have 0 as smallest digit and 7 as largest digit. 23
740, 760, 1071, 1740, 2074, 2705, 2710, 2740, 2750, 2760, 3705, 3710, 3760, 4071, 4705, 4740, 4760, 5071, 5705, 5760, 6740, 7074, 7240, 7260, 7400, 7550, 7560, 7600, 7601, 7760, 10076, 10174, 10274, 10275, 10371, 10375, 10376, 10571, 10710, 10724, 10726, 10740 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
fQ[n_] := Block[{c = DigitCount@ n}, And[Plus @@ Take[c, {8, 9}] == 0, c[[7]] > 0, c[[10]] > 0]]; Select[Range@ 10800, fQ@ # && fQ[#^2] &] (* Michael De Vlieger, Apr 12 2015 *)
PROG
(PARI) is(n) = vecmin(digits(n))==0 && vecmin(digits(n^2))==0 && vecmax(digits(n))==7 && vecmax(digits(n^2))==7
CROSSREFS
Sequence in context: A066404 A066402 A243778 * A105391 A319043 A044984
KEYWORD
nonn,base
AUTHOR
Felix Fröhlich, Apr 05 2015
STATUS
approved

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Last modified July 17 10:03 EDT 2024. Contains 374375 sequences. (Running on oeis4.)