A158304 Numbers k such that k^2 contains no digit greater than 4.

0, 1, 2, 10, 11, 12, 18, 20, 21, 32, 38, 48, 49, 100, 101, 102, 110, 111, 120, 149, 152, 179, 180, 182, 200, 201, 210, 318, 320, 321, 332, 338, 348, 351, 361, 362, 380, 451, 452, 462, 480, 482, 490, 548, 549, 649, 1000, 1001, 1002, 1010, 1011, 1012, 1020, 1021

Offset: 1

Author

N. J. A. Sloane, May 23 2010

Keywords

• nonn
• base

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• Erich Friedman, What's Special About This Number?

Crossrefs

Cf. A158082, A136810.

Programs

Maple

A158304 := proc(n) option remember; if n= 1 then 0; else for a from procname(n-1)+1 do d := convert(convert(a^2,base,10),set) ; if max(op(d)) <= 4 then return a; end if; end do; end if; end proc:
seq(A158304(n),n=1..100) ; # R. J. Mathar, May 23 2010

Mathematica

Select[Range[0,1100],Max[IntegerDigits[#^2]]<5&] (* Harvey P. Dale, Nov 06 2016 *)

Extensions

Extended by several correspondents, May 24 2010