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 A099084 #12 Sep 13 2024 00:39:06 %S A099084 1,3,27,663,6919 %N A099084 Numbers k such that 1.2. ... .k-1.k + 4 is a prime (dot between numbers means concatenation). %C A099084 Each term is odd and next term is greater than 2500. Prime corresponding to the next term has more than 8900 digits. Number of digits of primes corresponding to the four known terms of this sequence are respectively 1,3,45 & 1881. %C A099084 Next term is greater than 25000. - _Michael S. Branicky_, Sep 12 2024 %e A099084 27 is in the sequence because 123456789101112131415161718192021222324252627 + 4 is a prime. %Y A099084 Cf. A099081, A099082, A099083. %K A099084 base,more,nonn %O A099084 1,2 %A A099084 _Farideh Firoozbakht_, Nov 03 2004 %E A099084 a(5) from _Michael S. Branicky_, Jun 20 2023