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 A033561 #15 Mar 09 2025 05:12:30 %S A033561 7,13,19,23,31,37,41,53,67,89,101,103,107,109,137,139,157,163,167,191, %T A033561 199,227,233,251,257,263,271,277,293,311,313,331,349,367,373,383,389, %U A033561 397,409,431,433,443,461,467,503,509,557,563,569,571,577,587,599,601,607 %N A033561 Primes p such that 6!+p is also prime. %H A033561 Amiram Eldar, <a href="/A033561/b033561.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Vincenzo Librandi) %t A033561 Select[Prime[Range[800]], PrimeQ[# + 720]&] (* _Vincenzo Librandi_, Apr 10 2013 *) %o A033561 (Magma) [p: p in PrimesUpTo(800)|IsPrime(p+720)]; // _Vincenzo Librandi_, Apr 10 2013 %o A033561 (PARI) isok(k) = isprime(k) && sigma(k + 720) == sigma(k) + 720; \\ _Amiram Eldar_, Mar 08 2025 %Y A033561 Cf. A054984. %K A033561 nonn,easy %O A033561 1,1 %A A033561 _Jeff Burch_