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 A064278 #30 Sep 22 2024 15:21:04
%S A064278 1,2,3,4,5,6,9,11,17,18,25,31,40,96,174,193,204,269,523,650,659,797,
%T A064278 1437,1862,2515,4983,5557,11429
%N A064278 Numbers k such that k! + prime(k) is prime.
%C A064278 The numbers corresponding to 2515 and 4983 are probable primes. [_Farideh Firoozbakht_, Oct 15 2009]
%C A064278 a(28) > 10000. - _Giovanni Resta_, Mar 16 2014
%e A064278 n=5: 5! = 120 and prime(5) = 11, 120+11 = 131.
%e A064278 6 is listed because 6!+prime(6) = 720+13 = 733 is prime.
%t A064278 Do[ If[ PrimeQ[ n! + Prime[ n ] ], Print[ n ] ], {n, 1, 700} ]
%t A064278 Select[Range[1000], PrimeQ[#! + Prime[#]] &] (* _Vincenzo Librandi_, Mar 05 2015 *)
%o A064278 (PARI) for(n=1, 100, if (isprime(n!+prime(n)), print1(n, ", ")))
%o A064278 (Magma) [n: n in [1..200] | IsPrime(Factorial(n)+ NthPrime(n))]; // _Vincenzo Librandi_, Mar 05 2015
%Y A064278 Cf. A063499 (Primes of form prime(n) + n!). [_Alexander R. Povolotsky_, Aug 13 2008]
%K A064278 nonn
%O A064278 1,2
%A A064278 _Jason Earls_, Sep 24 2001
%E A064278 More terms from _Robert G. Wilson v_, Sep 28 2001
%E A064278 More terms from John Sillcox (JMS21187(AT)aol.com), Apr 05 2003
%E A064278 a(25)-a(26) from _Farideh Firoozbakht_, Oct 15 2009
%E A064278 a(27) from _Giovanni Resta_, Mar 16 2014
%E A064278 a(28) from _Michael S. Branicky_, Sep 22 2024