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 A101323 #17 Sep 08 2022 08:45:16 %S A101323 1,2,3,5,6,7,10,12,101,117,227,884,1323,2167,3483,6274,7887 %N A101323 Numbers n such that 2^n*(n+1)!-1 is prime. %C A101323 a(18) > 10^4.- _Robert Price_, Mar 08 2015 %t A101323 Select[Range[1000],PrimeQ[2^# (#+1)!-1]&] (* _Harvey P. Dale_, Nov 23 2014 *) %o A101323 (Magma) [n: n in [0..500] | IsPrime(2^n*Factorial(n+1)-1)]; // _Vincenzo Librandi_, Mar 08 2015 %o A101323 (PARI) is(n)=ispseudoprime(2^n*(n+1)!-1) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A101323 Cf. A093155. %K A101323 nonn %O A101323 1,2 %A A101323 _Jorge Coveiro_, Dec 24 2004 %E A101323 a(12) from _Harvey P. Dale_, Nov 23 2014 %E A101323 a(13)-a(17) from _Robert Price_, Mar 08 2015