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 A252791 #18 May 02 2022 01:38:28 %S A252791 2,3,5,7,11,23,41,55,73,91,131,199,221,287 %N A252791 Numbers m such that 6^m + m is a semiprime. %C A252791 From _Kevin P. Thompson_, May 01 2022: (Start) %C A252791 a(15) >= 335. %C A252791 391, 443, 607, 683, 737, and 745 are also terms in this sequence. (End) %H A252791 FactorDB, <a href="http://factordb.com/index.php?id=1100000000613180791">Status of 6^335+335</a> %e A252791 2 is in this sequence because 6^2+2 = 2*19 is semiprime. %e A252791 7 is in this sequence because 6^7+7 = 271*1033 and these two factors are prime. %t A252791 Select[Range[90], PrimeOmega[6^# + #]==2 &] %o A252791 (Magma) IsSemiprime:=func<i | &+[d[2]: d in Factorization(i)] eq 2>; [m: m in [1..90] | IsSemiprime(s) where s is 6^m+m]; %Y A252791 Cf. similar sequences listed in A252788. %Y A252791 Cf. A252659. %K A252791 nonn,more %O A252791 1,1 %A A252791 _Vincenzo Librandi_, Dec 25 2014 %E A252791 a(10)-a(14) by _Luke March_, Jul 08 2015