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 A343589 #23 Nov 20 2021 11:36:35 %S A343589 3,7,13,3121,31,43,549755813881,73,991,1321,248821,157,2731,211,241, %T A343589 34271896307617,307,6841,13107199999999999999981,421,463, %U A343589 141050039560662968926081,331753,601,17551,7625597484961,757,1816075630094014572464024421543167816955354437761 %N A343589 Smallest prime of the form n^k-(n-1) or 0 if no such prime exists. %C A343589 All values up to n=70 have been found and proved to be primes. n=71 has k=3019 and gives a probable prime. %C A343589 See A113516, which gives the k values and is the main entry for these primes, for more extensively researched information. - _Peter Munn_, Nov 20 2021 %H A343589 Blake Branstool, <a href="/A343589/b343589.txt">Table of n, a(n) for n = 2..70</a> %e A343589 For n=2 and k=2, 2^2-(2-1)=3 thus a(2)=3. k is 2 as well for n=3,4. %e A343589 For n=5 the first k to result in a prime is 5, 5^5-(5-1)=3121 thus a(5)=3121. %o A343589 (PARI) a(n) = my(k=1, p); while (!isprime(p=n^k-(n-1)), k++); p; \\ _Michel Marcus_, Nov 17 2021 %Y A343589 A113516 gives the k values. %Y A343589 Cf. A076846, A084741, A084745, A346154. %K A343589 nonn %O A343589 2,1 %A A343589 _Blake Branstool_, Apr 20 2021 %E A343589 Name revised by _Peter Munn_, Nov 16 2021