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 A076683 #15 Jul 04 2024 19:58:55 %S A076683 3,7,8,15,19,29,36,43,51,158,160,203,432,909,1235,3209,8715,9707 %N A076683 Numbers k such that 7*k! + 1 is prime. %C A076683 a(17) > 5830. - _Jinyuan Wang_, Feb 05 2020 %C A076683 a(19) > 12000. - _Michael S. Branicky_, Jul 04 2024 %e A076683 k = 3 is here because 7*3! + 1 = 43 is prime. %o A076683 (PARI) is(k) = ispseudoprime(7*k!+1); \\ _Jinyuan Wang_, Feb 05 2020 %o A076683 (Python) %o A076683 from sympy import isprime %o A076683 from math import factorial %o A076683 def aupto(m): return [k for k in range(m+1) if isprime(7*factorial(k)+1)] %o A076683 print(aupto(300)) # _Michael S. Branicky_, Mar 07 2021 %Y A076683 Cf. A002981, A051915, A076679, A076680, A076681, A076682, A178488, A180626, A126896. %K A076683 nonn,more %O A076683 1,1 %A A076683 Phillip L. Poplin (plpoplin(AT)bellsouth.net), Oct 25 2002 %E A076683 a(17)-a(18) from _Michael S. Branicky_, Jul 04 2024