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 A114973 #19 Sep 08 2022 08:45:23 %S A114973 1,2,4,6,8,9,84,288,628 %N A114973 Numbers n such that 5^n + n^5 is a semiprime. %C A114973 a(10) >= 868. - _Hugo Pfoertner_, Jul 28 2019 %H A114973 <a href="http://factordb.com/index.php?query=5%5E868%2B868%5E5">Status of 5^868-868^5 in factordb.com</a>. %e A114973 2 is OK because 5^2 + 2^5 = 25 + 32 = 57 = 3*19 (semiprime). %t A114973 Select[Range[100],PrimeOmega[5^# + #^5]==2&] (* _Vincenzo Librandi_, May 21 2014 *) %o A114973 (Magma)IsSemiprime:=func< n|&+[k[2]: k in Factorization(n)] eq 2 >; [n: n in [1..85]|IsSemiprime(5^n+n^5)]; // _Vincenzo Librandi_, Dec 16 2010 %Y A114973 Cf. A094133, A114970, A114971, A114974. %K A114973 nonn,more,hard %O A114973 1,2 %A A114973 _Zak Seidov_, Feb 22 2006 %E A114973 a(8), a(9) from _Hugo Pfoertner_, Jul 28 2019