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 A186688 #9 Sep 08 2022 08:45:55
%S A186688 82,626,2402,4097,10001,14642,20737,28562,38417,83522,104977,194482,
%T A186688 234257,279842,456977,707282,810001,1048577,1500626,1679617,2085137,
%U A186688 2313442,2560001,3111697,6250001,7311617,10556002,11316497,13845842,14776337,17850626,21381377,25411682
%N A186688 Semiprimes of the form n^4 + 1.
%H A186688 Vincenzo Librandi, <a href="/A186688/b186688.txt">Table of n, a(n) for n = 1..1000</a>
%e A186688 4097 is a member because 4097 = 8^4 + 1 = 17*241.
%t A186688 semiPrimeQ[n_] := Total[FactorInteger[n]][[2]] == 2; Select[ Range[200]^4
%t A186688 +1, semiPrimeQ]
%t A186688 Select[Table[n^4 + 1, {n, 80}], PrimeOmega[#] == 2&] (* _Vincenzo Librandi_, Sep 22 2012 *)
%o A186688 (Magma) IsSemiprime:= func<n | &+[d[2]: d in Factorization(n)] eq 2>; [s: n in [1..75] | IsSemiprime(s) where s is n^4 + 1]; // _Vincenzo Librandi_, Sep 22 2012
%Y A186688 Cf. A144255.
%K A186688 nonn,easy
%O A186688 1,1
%A A186688 _Michel Lagneau_, Feb 25 2011