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 A276199 #14 Aug 31 2016 09:12:40
%S A276199 3,31,31469,314107,314159,314159,314159207,3141592603,31415926541,
%T A276199 314159265307,314159265359,3141592653581,314159265358909,
%U A276199 3141592653589711,31415926535897921,314159265358979347,3141592653589793239,3141592653589793239,314159265358979323861
%N A276199 Smallest prime that begins with at least n digits of Pi.
%H A276199 Dana Jacobsen, <a href="/A276199/b276199.txt">Table of n, a(n) for n = 1..997</a> (first 28 terms from José Eduardo Gaboardi de Carvalho)
%e A276199 a(7) = 314159207, begins with first 7 digits of Pi = 3.141592653...
%o A276199 (Perl) use ntheory ":all"; sub a276199 { my $l=shift; my $p="3".substr(Pi($l+20),2,$l-1); for my $dig (0 .. 20) { my $add = "0" x $dig; do { return "$p$add" if is_prime("$p$add"); } while length(++$add) == $dig; } } # _Dana Jacobsen_, Aug 30 2016
%Y A276199 Cf. A005042.
%K A276199 nonn,base
%O A276199 1,1
%A A276199 _José Eduardo Gaboardi de Carvalho_, Aug 24 2016