A134843 - OEIS

%I #11 Nov 15 2023 16:49:29

%S 32,33,45,47,48,49,51,52,53,55,64,71,78,84,95,97,98,99,101,102,103,

%T 104,105,138,142,143,144,145,147,148,149,151,152,153,155,174,175,176,

%U 179,195,197,198,199,201,202,203,205,217,224,225,226,241,243,245,246,247

%N Numbers n not divisible by 10 such that n^2 contains a 0.

%H Harvey P. Dale, <a href="/A134843/b134843.txt">Table of n, a(n) for n = 1..1000</a>

%H J. Browkin, <a href="https://web.archive.org/web/20071220044826/http://www.impan.gov.pl/Kryptologia/GROEB1.pdf">Groebner basis</a>.

%e a(1)=32 because 1024=32^2

%t a = {}; Do[Do[Do[k = 100s + 10n + m; w = IntegerDigits[k^2]; If[MemberQ[w, 0], AppendTo[a, k]], {m, 1, 9}], {n, 0, 9}], {s, 0, 9}]; Union[a]

%t Select[Range[300],Mod[#,10]!=0&&DigitCount[#^2,10,0]>0&] (* _Harvey P. Dale_, Nov 15 2023 *)

%Y Cf. A134844, A134845.

%K nonn,base

%O 1,1

%A _Artur Jasinski_, Nov 13 2007