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 A305076 #28 Jun 11 2024 09:44:23 %S A305076 2,4,5,8,9,15,29,213,666,1360,3932,7916 %N A305076 Numbers k such that prime(k)^k - primorial(k - 1) is prime. %C A305076 Numbers k such that A304917(k) is prime. %C A305076 a(12) > 4000 if it exists. %e A305076 n = 1 gives 2 - 1 = 1. n=2 gives 3^2 - 2 = 7, so 2 is the first term. %p A305076 N:=2000: %p A305076 for X from 1 to N do %p A305076 Z:=mul(ithprime(i),i=1..(X-1)); %p A305076 Y:=(ithprime(X)^X - Z); %p A305076 if isprime(Y) then print(X); %p A305076 end if %p A305076 end do: %t A305076 Select[Range@ 700, PrimeQ[Prime[#]^# - Product[Prime@ i, {i, # - 1}]] &] (* _Michael De Vlieger_, Jul 19 2018 *) %o A305076 (PARI) isok(k) = isprime(prime(k)^k - prod(j=1, k-1, prime(j))); \\ _Michel Marcus_, Jun 09 2018 %Y A305076 Cf. A062457, A002110, A304917. %K A305076 nonn,more %O A305076 1,1 %A A305076 _David James Sycamore_, May 24 2018 %E A305076 a(12) from _Michael S. Branicky_, Jun 11 2024