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 A261639 #12 Aug 28 2015 18:07:28 %S A261639 2,3,4,5,19,110 %N A261639 Values of n such that prime(n+1)!/prime(n) + 1 is a prime number. %C A261639 a(1) = 2, a(2) = 3, a(3) = 4, a(4) = 5. It can be seen as a nice consecutiveness on sequence for first four items. Another point is that sequence of prime(n+1)! / prime(n) is observed in A260754. %C A261639 a(7) > 2300. - _Giovanni Resta_, Aug 28 2015 %e A261639 For n=2 the (prime(n+1)! / prime(n)) + 1 = 41. 41 is prime. %o A261639 (PARI) for(n=1, 1e3, if(isprime(k=((prime(n+1)!/prime(n))+1)), print1(n", "))) %Y A261639 Cf. A260754. %K A261639 nonn,more %O A261639 1,1 %A A261639 _Altug Alkan_, Aug 27 2015