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 A228419 #21 Mar 19 2024 12:28:18
%S A228419 1,8,67,539,5034,45549,416913,3570781,32517377,294828478,2681147149,
%T A228419 23720397369,212156228217
%N A228419 Count of the first 10^n primes which do not contain the digit 7.
%F A228419 a(n) <= 9^n. - _Charles R Greathouse IV_, May 21 2014
%e A228419 a(1) = 8 since there are 8 primes in the first 10 (through 29) that do not contain a 7. Namely: 2, 3, 5, 11, 13, 19, 23, 29.
%t A228419 Table[Length[Select[Range[10^n], DigitCount[Prime[#], 10, 7] == 0 &]], {n, 0, 5}] (* _Robert Price_, Mar 23 2020 *)
%Y A228419 Cf. A231412, A228413-A228421, A097952, A091634-A091643.
%K A228419 more,nonn,base,hard
%O A228419 0,2
%A A228419 _Robert Price_, Nov 09 2013
%E A228419 a(12) from _Lucas A. Brown_, Mar 19 2024