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 A057824 #24 Jul 11 2025 01:25:17 %S A057824 5,11,59,419,839,232792559,5354228879,2329089562799,144403552893599, %T A057824 442720643463713815199,591133442051411133755680799, %U A057824 69720375229712477164533808935312303556799 %N A057824 Primes p such that p+1 is LCM(1,...,m) for some (usually more than one) m. %C A057824 Prime numbers of the form A051451(k)-1. %C A057824 Primes p = LCM(1,...,m) - 1, where m is a prime power. (The prime powers give all values, and do so uniquely.) - _Daniel Forgues_, Apr 28 2014 %C A057824 This unique prime power m associated with a(n) is m = A385564(n). - _Jeppe Stig Nielsen_, Jul 09 2025 %H A057824 Amiram Eldar, <a href="/A057824/b057824.txt">Table of n, a(n) for n = 1..23</a> %e A057824 232792559 + 1 = LCM(1,...,m) for m = 19, 20, 21, 22. %t A057824 Select[FoldList[LCM, Select[Range[100], PrimePowerQ]] - 1, PrimeQ] (* _Amiram Eldar_, Aug 18 2024 *) %o A057824 (PARI) L=1; for(n=2,1e3,if(isprimepower(n,&p) && ispseudoprime((L*=p)-1), print1(L-1", "))) \\ _Charles R Greathouse IV_, Apr 28 2014 %Y A057824 Cf. A003418, A051451, A049536, A049537, A385564. %K A057824 nonn %O A057824 1,1 %A A057824 _Labos Elemer_, Nov 08 2000