A328783 Numbers k such that k and k^2 contain at least one zero but not the same number of 0's.

10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 101, 102, 103, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 201, 202, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 301, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 401, 410, 420, 430, 440, 450, 460, 470

Offset

1,1

Comments

This sequence is one of the three sequences whose numbers k and k^2 don't contain the same number of 0, the two others are A104315 and A134844.

Links

Giovanni Resta, Table of n, a(n) for n = 1..10000

Example

201 and 40401 = 201^2 have both at least one zero but not the same number of 0 in their decimal expansion, hence, 201 is a term.

Maple

f:= n-> numboccur(0, convert(n, base, 10)):
q:= n-> ((x, y)-> x>0 and y>0 and x<>y)(f(n), f(n^2)):
select(q, [$0..500])[];  # Alois P. Heinz, Oct 28 2019

Mathematica

Select[Range[0, 470], (x = DigitCount[#, 10, 0]) > 0 && (y = DigitCount[ #^2, 10, 0]) > 0 && x != y &] (* Giovanni Resta, Feb 27 2020 *)

Crossrefs

Cf. A052040, A104315, A134844, A328780, A328781, A328782.

Sequence in context: A098394 A057169 A330562 * A342855 A201014 A096092

Adjacent sequences: A328780 A328781 A328782 * A328784 A328785 A328786

Keyword

nonn,base

Author

Bernard Schott, Oct 28 2019

Extensions

More terms from Alois P. Heinz, Oct 28 2019

Status

approved