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 A261714 #24 Sep 08 2022 08:46:13 %S A261714 0,2,4,8,72 %N A261714 Numbers n such that n! + 2^n + 1 is prime. %C A261714 Inspired by A007611. %C A261714 First three prime numbers of the form n! + 2^n +1 with positive n value are 7, 41, 40577. %C A261714 a(5) > 30000. - _Giovanni Resta_, Aug 30 2015 %e A261714 For n=2, n! + 2^n + 1 = 2! + 2^2 + 1 = 7, which is prime. %t A261714 Select[Range@ 2000, PrimeQ[#! + 2^# + 1] &] (* _Michael De Vlieger_, Aug 29 2015 *) %o A261714 (PARI) for(n=1, 1e3, if(isprime(k=(n!+2^n+1)), print1(n", "))) %o A261714 (Magma) [n: n in [1..300] | IsPrime(Factorial(n)+2^n+1)]; // _Vincenzo Librandi_, Aug 30 2015 %o A261714 (PFGW) ABC2 $a! + 2^$a + 1 %o A261714 a: from 0 to 30000 %o A261714 _Charles R Greathouse IV_, Sep 08 2015 %Y A261714 Cf. A007611. %K A261714 nonn,more,hard %O A261714 1,2 %A A261714 _Altug Alkan_, Aug 29 2015