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 A360740 #29 Mar 13 2023 16:23:27 %S A360740 4,39,259,327,403,579,679,1027,1159,1299,1603,1939,2119,2307,3139, %T A360740 3603,4359,4627,6087,6403,7747,9607,10003,10407,10819,11667,13459, %U A360740 13927,14403,16387,18499,21907,23107,26899,28903,30279,30979,33127,35347,36103,36867,38419 %N A360740 Semiprimes of the form k^2 + 3. %C A360740 A242331 gives the corresponding values of k. %F A360740 a(n) = A242331(n)^2 + 3. %e A360740 259 is a term because 16^2 + 3 = 259 = 7*37. %t A360740 Select[Range[0, 200]^2 + 3, PrimeOmega[#] == 2 &] (* _Amiram Eldar_, Feb 18 2023 *) %Y A360740 Cf. A001358, A085722, A117950, A144255, A242330, A242331. %K A360740 nonn,easy %O A360740 1,1 %A A360740 _Elmo R. Oliveira_, Feb 18 2023