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 A304456 #20 Jun 03 2018 11:57:10
%S A304456 22,4,454,300746,111614,14491726,1096669582,42205941082,85933755478,
%T A304456 746001905114,39682041123518
%N A304456 Least semiprime of a run of exactly n even semiprimes.
%C A304456 Runs of semiprimes of the same parity: {4, 6}, {9}, {10, 14}, {15, 21}, {22}, {25}, {26}, {33}, {34}, {35}, {38}, {39}, {46}, {49, 51, 55, 57}, {58, 62}, {65, 69}, {74}, {77}, {82}, {85}, {86}, {87, 91, 93}, {94}, ...
%C A304456 a(12) > 2*10^14.
%e A304456 a(1) = 22 since it is the first occurrence of a single even semiprime;
%e A304456 a(2) = 4 since 4 is the first of two consecutive even semiprimes in the sequence of semiprimes;
%e A304456 a(3) = 454 since it is the first of three consecutive even semiprimes in the sequence of semiprimes; etc.
%t A304456 SplitBy[ Select[ Range@ 100, PrimeOmega@# == 2 &], Mod[#, 2] &] (* to view the runs of semiprimes of the same parity *)
%Y A304456 Cf. A001358, A304457, A304458.
%K A304456 nonn,more
%O A304456 1,1
%A A304456 _Zak Seidov_, _Silvester Resnik_ and _Robert G. Wilson v_, May 12 2018