A136817 -id:A136817 - cp's OEIS frontend

A256631 Numbers n such that the decimal expansions of both n and n^2 have 0 as smallest digit and 5 as largest digit.

50, 105, 150, 205, 350, 450, 500, 501, 502, 505, 550, 1005, 1015, 1050, 1055, 1105, 1150, 1205, 1450, 1500, 1501, 1550, 2005, 2050, 2055, 2105, 2305, 2350, 3350, 3500, 4500, 5000, 5001, 5002, 5005, 5010, 5011, 5012, 5015, 5020, 5021, 5032, 5045, 5050, 5055

Offset: 1

Felix Fröhlich, Apr 05 2015

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

Cf. A136817, A256630, A256633, A256634, A256708, A256709, A256889, A257086.

fQ[n_] := Block[{c = DigitCount@ n}, And[Plus @@ Take[c, {6, 9}] == 0, c[[5]] > 0, c[[10]] > 0]]; Select[Range@ 5100, fQ@ # && fQ[#^2] &] (* Michael De Vlieger, Apr 12 2015 *)
Select[Range[5100],Min[IntegerDigits[#]]==0&&Max[IntegerDigits[#] ]== 5 && Min[IntegerDigits[#^2]]==0&&Max[IntegerDigits[#^2]]==5&] (* Harvey P. Dale, Jan 19 2020 *)

is(n) = vecmin(digits(n))==0 && vecmin(digits(n^2))==0 && vecmax(digits(n))==5 && vecmax(digits(n^2))==5

A136816 Numbers k such that k and k^2 use only the digits 0, 1, 2 and 4.

Original entry on oeis.org

0, 1, 2, 10, 11, 12, 20, 21, 100, 101, 102, 110, 120, 200, 201, 210, 1000, 1001, 1002, 1010, 1011, 1012, 1020, 1021, 1100, 1101, 1102, 1200, 1201, 2000, 2001, 2010, 2011, 2100, 2101, 10000, 10001, 10002, 10010, 10011, 10012, 10020, 10021, 10100, 10110, 10120, 10200, 10210, 11000, 11001, 11002, 11010, 11011, 11020, 12000, 12001, 12010, 20000, 20001

Offset: 1

Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008

Generated with DrScheme.

Subsequence of A136817-A136821. - M. F. Hasler, Jan 24 2008

			21010001010^2 = 441420142440201020100.

Jonathan Wellons, Table of n, a(n) for n = 1..1569
J. Wellons, Tables of Shared Digits [archived]

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 *)

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A256631 Numbers n such that the decimal expansions of both n and n^2 have 0 as smallest digit and 5 as largest digit.

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A136816 Numbers k such that k and k^2 use only the digits 0, 1, 2 and 4.

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

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