A054032 Numbers n such that n^2 contains exactly 4 different digits.

32, 33, 36, 37, 42, 43, 44, 48, 49, 51, 52, 53, 54, 55, 57, 59, 61, 64, 66, 69, 71, 72, 73, 74, 78, 79, 82, 84, 86, 87, 89, 93, 95, 96, 98, 99, 103, 104, 105, 106, 112, 114, 115, 123, 125, 127, 130, 132, 135, 138, 139, 140, 143, 145, 146, 151, 155, 156, 157, 158

Offset: 1

Author

Asher Auel, Feb 29 2000

Keywords

• nonn
• base

Links

• T. D. Noe, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A016069, A054031, A054033, A054034, A054035, A054036, A054037, A054038, A054039.

Programs

Maple

f := []; for i from 0 to 200 do if nops({op(convert(i^2,base,10))})=4 then f := [op(f),i] fi; od; f;

Mathematica

t = {}; n = -1; While[Length[t] < 50, n++; If[Length[Union[IntegerDigits[n^2]]] == 4, AppendTo[t, n]]] (* T. D. Noe, Apr 26 2013 *)

PARI

is(n)=#Set(digits(n^2))==4 \\ Charles R Greathouse IV, Feb 11 2017