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 A228414 #23 Mar 19 2024 12:29:29
%S A228414 0,7,77,697,6497,55552,512100,4710641,42205969,341224891,2787791578,
%T A228414 22971326749,190650687957
%N A228414 Count of the first 10^n primes which do not contain the digit 2.
%F A228414 a(n) < 9^n. - _Charles R Greathouse IV_, May 21 2014
%e A228414 a(1) = 7 since there are 7 primes less than 29 (the 10th prime) that do not contain a 2. Namely: 3, 5, 7, 11, 13, 17, 19.
%t A228414 Table[Length[Select[Range[10^n], DigitCount[Prime[#], 10, 2] == 0 &]], {n, 0, 5}] (* _Robert Price_, Mar 23 2020 *)
%Y A228414 Cf. A231412, A228413-A228421, A097952, A091634-A091643.
%K A228414 more,nonn,base,hard
%O A228414 0,2
%A A228414 _Robert Price_, Nov 09 2013
%E A228414 a(12) from _Lucas A. Brown_, Mar 19 2024