A254071 Numbers n such that the decimal expansions of both n and n^2 have 4 as the digit with the smallest value and 8 as the digit with the largest value.

684, 6684, 8874, 66684, 68474, 74758, 76478, 86478, 666684, 668474, 675684, 744758, 766458, 6666684, 6668474, 6675684, 6748678, 6845784, 7586478, 8686574, 8875684, 66666684, 66756684, 74744758, 74758576, 75858874, 75867574, 76464878, 86878458, 87546878

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..1000

Mathematica

fQ[n_] := Block[{c = DigitCount@ n}, And[Plus @@ Take[c, {1, 3}] == 0, Plus @@ Take[c, {9, 10}] == 0, c[[4]] > 0, c[[8]] > 0]]; Select[Range@ 1000000, fQ@ # && fQ[#^2] &] (* Michael De Vlieger, May 05 2015 *)

Prog

(PARI) is(n) = vecmin(digits(n))==4 && vecmin(digits(n^2))==4 && vecmax(digits(n))==8 && vecmax(digits(n^2))==8

Crossrefs

Cf. A256630, A256631, A256633, A256634, A256708, A256709, A256889, A257197, A257210, A257211, A256601, A257310, A249915, A257123, A257368, A257485, A257486, A257498, A238553.

Sequence in context: A245393 A252856 A184089 * A022050 A107514 A116219

Adjacent sequences: A254068 A254069 A254070 * A254072 A254073 A254074

Keyword

nonn,base

Author

Felix Fröhlich, May 03 2015

Status

approved