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 A057825 #15 Jul 13 2022 19:25:46 %S A057825 3,4,5,6,7,8,19,20,21,22,23,24,29,30,32,33,34,35,36,47,48,61,62,63,97, %T A057825 98,99,100,181,182,183,184,185,186,187,188,189,190,233,234,235,236, %U A057825 237,238,307,308,309,310,401,402,403,404,405,406,407,408,887,888,889,890 %N A057825 Values of k for which A003418(k) - 1 is prime. %C A057825 Fewer distinct primes than distinct values of a(n) are generated. So, e.g., k = 97, 98, 99, 100 all correspond to lcm([1..97]) - 1 = 69720375229712477164533808935312303556799, a prime. %H A057825 Jinyuan Wang, <a href="/A057825/b057825.txt">Table of n, a(n) for n = 1..125</a> %o A057825 (PARI) isok(k) = ispseudoprime(lcm(vector(k, i, i))-1); \\ _Jinyuan Wang_, May 02 2020 %Y A057825 Cf. A003418, A049536, A049537, A051451. %K A057825 nonn %O A057825 1,1 %A A057825 _Labos Elemer_, Nov 08 2000