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 A064401 #22 Apr 21 2025 12:10:14
%S A064401 4,5,7,12,14,15,16,17,18,20,30,37,39,49,52,66,86,162,165,202,235,250,
%T A064401 366,419,1169,1311,1916,3032,3211,3335,4650,6199,7762,12776
%N A064401 Numbers k such that k! - prime(k) is prime.
%C A064401 a(34) > 12500. - _Giovanni Resta_, Mar 16 2014
%t A064401 Do[ If[ PrimeQ[ n! - Prime[ n ] ], Print[ n ] ], {n, 1, 600} ]
%t A064401 Select[Range[2000], PrimeQ[#! - Prime[#]] &] (* _Vincenzo Librandi_, Mar 05 2015 *)
%o A064401 (Magma) [n: n in [1..200] | IsPrime(Factorial(n)- NthPrime(n))]; // _Vincenzo Librandi_, Mar 05 2015
%Y A064401 Cf. A064278.
%K A064401 nonn,hard,more
%O A064401 1,1
%A A064401 _Robert G. Wilson v_, Sep 28 2001
%E A064401 a(25)-a(27) from _Farideh Firoozbakht_, Feb 28 2004
%E A064401 a(28)-a(33) from _Giovanni Resta_, Mar 16 2014
%E A064401 a(34) from _Michael S. Branicky_, Apr 20 2025