This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A328782 #23 Feb 27 2020 07:51:55 %S A328782 0,104,105,203,205,302,303,305,402,403,405,504,505,506,507,508,509, %T A328782 601,602,603,605,609,701,702,703,705,708,709,801,802,803,805,901,902, %U A328782 903,905,906,1006,1007,1008,1009,1011,1012,1013,1014,1016,1017,1018,1019,1021 %N A328782 Integers k such that k and k^2 contain the same number > 0 of digits zero in their decimal expansion. %H A328782 Giovanni Resta, <a href="/A328782/b328782.txt">Table of n, a(n) for n = 1..10000</a> %e A328782 703 and 494209 = 703^2 both have one zero digit in their decimal expansion. %p A328782 f:= n-> numboccur(0, convert(n, base, 10)): %p A328782 q:= n-> ((x, y)-> x>0 and x=y)(f(n), f(n^2)): %p A328782 select(q, [$0..1030])[]; # _Alois P. Heinz_, Oct 28 2019 %t A328782 Select[Range[0, 1100], DigitCount[#, 10, 0] == DigitCount[#^2, 10, 0] > 0 &] (* _Giovanni Resta_, Feb 27 2020 *) %Y A328782 Equals A328781 \ A052040. %Y A328782 Cf. A104315, A134844, A328780, A328783. %K A328782 nonn,base %O A328782 1,2 %A A328782 _Bernard Schott_, Oct 28 2019 %E A328782 More terms from _Alois P. Heinz_, Oct 28 2019