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 A091635 #22 Apr 17 2021 09:08:11 %S A091635 4,17,101,670,4675,34425,262549,2051466,16312743,131464721,1071368863, %T A091635 8809580516,72986908554,608542410004 %N A091635 Number of primes less than 10^n which do not contain the digit 1. %F A091635 Number of primes less than 10^n after removing any primes with at least one digit 1. %F A091635 a(n) = A006880(n) - A091645(n). %e A091635 a(2) = 17 because of the 25 primes less than 10^2, 8 have at least one digit 1; 25-8 = 17. %t A091635 NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; c = 0; p = 1; Do[ While[ p = NextPrim[p]; p < 10^n, If[ Position[ IntegerDigits[p], 1] == {}, c++ ]]; Print[c]; p--, {n, 1, 8}] (* _Robert G. Wilson v_, Feb 02 2004 *) %o A091635 (Python) %o A091635 from sympy import sieve # import/use primerange for larger terms %o A091635 def a(n): return sum('1' not in str(p) for p in sieve.primerange(1, 10**n)) %o A091635 print([a(n) for n in range(1, 8)]) # _Michael S. Branicky_, Apr 17 2021 %Y A091635 Cf. A091634, A091636, A091637, A091638, A091639, A091640, A091641, A091642, A091643. %K A091635 nonn,base,more %O A091635 1,1 %A A091635 _Enoch Haga_, Jan 30 2004 %E A091635 Edited and extended by _Robert G. Wilson v_, Feb 02 2004 %E A091635 a(9)-a(12) from _Donovan Johnson_, Feb 14 2008 %E A091635 a(13) from _Robert Price_, Nov 08 2013 %E A091635 a(14) from _Giovanni Resta_, Mar 20 2017