A328783 - OEIS

%I #11 Feb 27 2020 07:52:02

%S 10,20,30,40,50,60,70,80,90,100,101,102,103,110,120,130,140,150,160,

%T 170,180,190,200,201,202,210,220,230,240,250,260,270,280,290,300,301,

%U 310,320,330,340,350,360,370,380,390,400,401,410,420,430,440,450,460,470

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

%C 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.

%H Giovanni Resta, <a href="/A328783/b328783.txt">Table of n, a(n) for n = 1..10000</a>

%e 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.

%p f:= n-> numboccur(0, convert(n, base, 10)):

%p q:= n-> ((x, y)-> x>0 and y>0 and x<>y)(f(n), f(n^2)):

%p select(q, [$0..500])[];  # _Alois P. Heinz_, Oct 28 2019

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

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

%K nonn,base

%O 1,1

%A _Bernard Schott_, Oct 28 2019

%E More terms from _Alois P. Heinz_, Oct 28 2019