A135251 - OEIS

A135251

Maximal number of zero digits in square of number with n digits not divisible by 10.

%I #3 Mar 31 2012 10:22:05

%S 0,1,3,4,6,8,10

%N Maximal number of zero digits in square of number with n digits not divisible by 10.

%t (*For a(7)*) mx = 0; Do[Do[Do[Do[Do[Do[Do[k = 10^6b + 10^5q + 10^4r + 10^3p + 10^2s + 10n + m; w = IntegerDigits[k^2]; ile = 0; Do[If[w[[t]] == 0, ile = ile + 1; If[ile > mx, mx = ile]], {t, 1, Length[w]}], {m, 1, 9}], {n, 0, 9}], {s, 0, 9}], {p, 0, 9}], {r, 0, 9}], {q, 0, 9}], {b, 1, 9}]; mx

%Y Cf. A134843, A134844, A134845, A134846, A134847, A134848, A134849, A135215, A135217, A135219, A135252, A135253.

%K base,nonn

%O 1,3

%A _Artur Jasinski_, Nov 24 2007