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 A384013 #9 May 20 2025 00:20:57 %S A384013 11,113,223,227,229,331,337,443,449,557,661,773,881,883,887,991,997, %T A384013 1103,1109,1117,1123,1129,1151,1153,1163,1171,1181,1187,1193,2203, %U A384013 2207,2213,2221,2237,2239,2243,2251,2267,2269,2273,2281,2287,2293,2297,3301,3307,3313 %N A384013 Primes with at least two identical leading digits. %t A384013 Select[Prime[Range[5,500]],Part[d=IntegerDigits[#],1]==Part[d,2] &] %Y A384013 Cf. A383978, A384014, A384015. %Y A384013 Subsequence of A050758. %Y A384013 Cf. A062353 (variant). %K A384013 nonn,base %O A384013 1,1 %A A384013 _Stefano Spezia_, May 17 2025