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 A228416 #26 Mar 19 2024 12:28:56
%S A228416 1,10,75,721,6637,60605,514809,4730382,43254591,392344689,3421561753,
%T A228416 31049600245,282499317912
%N A228416 Count of the first 10^n primes which do not contain the digit 4.
%F A228416 a(n) <= 9^n. - _Charles R Greathouse IV_, May 21 2014
%e A228416 a(1) = 10 since there are 10 primes in the first 10 (through 29) that do not contain a 4. Namely: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29.
%t A228416 Table[Length[Select[Range[10^n], DigitCount[Prime[#], 10, 4] == 0 &]], {n, 0, 5}] (* _Robert Price_, Mar 23 2020 *)
%Y A228416 Cf. A231412, A228413-A228421, A097952, A091634-A091643.
%K A228416 more,nonn,base,hard
%O A228416 0,2
%A A228416 _Robert Price_, Nov 09 2013
%E A228416 a(12) from _Lucas A. Brown_, Mar 19 2024