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 A300398 #27 Apr 03 2023 10:36:13 %S A300398 3,26,253,2515,25007,250110,2500209,25000135,250002220,2500000243, %T A300398 25000027724,250000009260 %N A300398 a(n) = number of primes that end in 3 among the first 10^n primes. %H A300398 Caldwell and Honaker, <a href="https://t5k.org/curios/page.php?curio_id=31995">Prime Curios!</a> %F A300398 a(n) = A185712(A006988(n)). - _Michel Marcus_, Mar 20 2018 %e A300398 a(1) = 3 because the first 10 primes are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, among which there are three primes ending in 3. %o A300398 (PARI) a(n) = #select(x->((x % 10) == 3), primes(10^n)); \\ _Michel Marcus_, Mar 07 2018 %Y A300398 Cf. A006988, A030431, A185712, A300397, A300399, A300400. %K A300398 nonn,base,more %O A300398 1,1 %A A300398 _G. L. Honaker, Jr._, Mar 05 2018 %E A300398 a(3)-a(8) from Chuck Gaydos %E A300398 a(9) from _Jon E. Schoenfield_, Mar 20 2018 %E A300398 a(10)-a(12) from _Giovanni Resta_, Mar 27 2018