A257085 -id:A257085 - cp's OEIS frontend

A256633 Numbers n such that the decimal expansions of both n and n^2 have 0 as smallest digit and 6 as largest digit.

60, 160, 460, 506, 560, 600, 601, 602, 605, 660, 1006, 1016, 1060, 1160, 1460, 1560, 1600, 1601, 1602, 1620, 2006, 2016, 2060, 2160, 2460, 2560, 3606, 4506, 4600, 4605, 4650, 5006, 5016, 5060, 5160, 5506, 5600, 5605, 5660, 6000, 6001, 6002, 6005, 6010, 6020

Offset: 1

Felix Fröhlich, Apr 05 2015

Felix Fröhlich, Table of n, a(n) for n = 1..10000

Cf. A256630, A256631, A256634, A256708, A256709, A256889, A257085.

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 *)
Select[Range[6100],With[{idn=IntegerDigits[#],idn2=IntegerDigits[#^2]},Min[idn]==Min[idn2]==0&&Max[idn]==Max[idn2]==6]&] (* Harvey P. Dale, Feb 06 2025 *)

is(n) = vecmin(digits(n))==0 && vecmin(digits(n^2))==0 && vecmax(digits(n))==6 && vecmax(digits(n^2))==6

A257086 Numbers n such that the decimal expansions of both n and n^2 only use the digits 0..5.

Original entry on oeis.org

0, 1, 2, 5, 10, 11, 12, 15, 20, 21, 32, 35, 45, 50, 55, 100, 101, 102, 105, 110, 111, 112, 115, 120, 145, 150, 152, 155, 200, 201, 205, 210, 211, 235, 320, 321, 332, 335, 350, 351, 450, 451, 452, 500, 501, 502, 505, 550, 1000, 1001, 1002, 1005, 1010, 1011, 1012, 1015, 1020, 1021, 1050, 1055, 1100

Offset: 1

Danny Rorabaugh, Apr 15 2015

			115 is in the list because 115 and 115^2 = 13225 do not use the digits 6, 7, 8, or 9.
121 is not in the list because 121^2 = 14641 uses the digit 6.
149 is not in the list because it uses the digit 9 (even though 149^2 = 22201 would be okay).

Danny Rorabaugh, Table of n, a(n) for n = 1..5000

Cf. A178501 (0..1), A136808(0..2), A136809(0..3), A136810 (0..4), A257085 (0..6).

Cf. A136817, A256631.

Select[Range@ 1100, Total@ Take[DigitCount[#], {6, 9}] == 0 && Total@ Take[DigitCount[#^2], {6, 9}] == 0 &] (* Michael De Vlieger, Apr 17 2015 *)

cp's OEIS Frontend

A256633 Numbers n such that the decimal expansions of both n and n^2 have 0 as smallest digit and 6 as largest digit.

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