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 A051453 #25 Jul 04 2025 14:29:24
%S A051453 1,2,3,4,5,7,9,19,25,31,47,89,127,139,1369,2251,3271,4253,4373,4549,
%T A051453 5449,13331,37123,55291,79633,105653
%N A051453 Prime powers such that 1 + lcm(1,2,...,p^w) is prime.
%e A051453 1 + lcm(1,2,..,89) = 718766754945489455304472257065075294401 is prime.
%o A051453 (PARI) ispp(n) = isprimepower(n) || n==1;
%o A051453 lista(nn) = {for (n=1, nn, if (ispp(n) && ispseudoprime(1+lcm([1..n])), print1(n, ", ")););} \\ _Michel Marcus_, Aug 26 2019
%Y A051453 Cf. A000961, A003418, A049536, A049537.
%K A051453 nonn,more
%O A051453 1,2
%A A051453 _Labos Elemer_
%E A051453 Corrected and extended by _Wouter Meeussen_, Apr 18 2003
%E A051453 a(18)-a(22) from _Jinyuan Wang_, May 02 2020
%E A051453 a(23)-a(24) from _Michael S. Branicky_, Apr 22 2023
%E A051453 a(25)-a(26) from _Michael S. Branicky_, Jul 04 2025