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 A330089 #78 Mar 16 2023 21:11:29
%S A330089 7,22,148,472,2632,14944,25312,349312,1645312,16274560,27565312,
%T A330089 163240960,1637104000,17758898176,36261548032,18847289344,
%U A330089 1280655450112,5778613350400,42629361516544,219654008209408,137946306445312,4629754071040000,53702255633760256,9828354353004544,404693465879805952
%N A330089 a(n) is the smallest integer k such that Omega(k) = n and Omega(2*k+1) = n+1 (where Omega is A001222).
%C A330089 Are all terms > 7 even? Is the sequence infinite?
%C A330089 If A115186(n + 1) is even then a(n) = A115186(n + 1) / 2. - _David A. Corneth_, Mar 23 2021
%H A330089 David A. Corneth, <a href="/A330089/b330089.txt">Table of n, a(n) for n = 1..27</a>
%e A330089 n=1: 7 is prime and 2*7+1 = 15 = 3*5 is semiprime A001358(6);
%e A330089 n=2: 22 = 2*11 is semiprime A001358(8) and 2*22+1 = 45 = 3*3*5 is 3-almost prime A014612(10).
%o A330089 (PARI) a(n) = {my(k=1); while ((bigomega(k) != n) || (bigomega(2*k+1) != (n+1)), k++); k;} \\ _Michel Marcus_, Aug 20 2020
%Y A330089 Cf. A001222, A001358, A014612, A115186.
%K A330089 nonn
%O A330089 1,1
%A A330089 _Zak Seidov_, Jul 26 2020
%E A330089 a(14)-a(18) from _Dana Jacobsen_, Aug 30 2020
%E A330089 More terms from _David A. Corneth_, Mar 23 2021