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 A046284 #13 Feb 16 2025 08:32:39
%S A046284 2,3,7,719,1033,2297,3037,11927
%N A046284 Primes p such that concatenation of primes from 2 through p is a prime.
%C A046284 "w_n = (P_1)(P_2) ... (P_n) [A019518], by which notation we mean that w_n is constructed in decimal by simple concatenation of digits [much like the Almost Natural numbers (A007376)]. For example, the first few w_n are 2, 23, 235, 2357, 235711, ... ." - Crandall and Pomerance
%D A046284 R. Crandall and C. Pomerance, Prime Numbers: A Computational Perspective, Springer, NY, 2001; see p. 72. [The 2002 printing states incorrectly that 5441 is a term.]
%H A046284 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConsecutiveNumberSequences.html">Consecutive Number Sequences.</a>
%H A046284 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/IntegerSequencePrimes.html">Integer Sequence Primes</a>
%H A046284 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Smarandache-WellinNumber.html">Smarandache-Wellin Number</a>
%e A046284 7 is a member, since 2357 is a prime.
%t A046284 a = ""; Do[a = StringJoin[a, ToString[ Prime[n]]]; If[ PrimeQ[ ToExpression[a]], Print[n]], {n, 1, 1429}]
%Y A046284 Cf. A019518, A033308, A069151. a(n) = prime(A046035(n)).
%K A046284 nonn,base
%O A046284 1,1
%A A046284 _Patrick De Geest_, Jun 15 1998
%E A046284 Additional comments from _Robert G. Wilson v_, Sep 10 2001