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 A217222 #26 Jun 13 2022 07:47:25
%S A217222 8129,237449,401429,452639,604487,858179,1471727,1999937,2376893,
%T A217222 2714987,3111977,3302039,3869237,4622087,7813559,9795449,10587899,
%U A217222 10630739,11389349,14186387,14924153,15142547,15757337,18017687,18271829,19732979,22715057,25402907
%N A217222 Initial terms of sets of 8 consecutive semiprimes with gap 2.
%C A217222 All terms == 11 (mod 18).
%C A217222 Also all terms of sets of 8 consecutive semiprimes are odd, e.g., {8129, 8131, 8133, 8135, 8137, 8139, 8141, 8143} is the smallest set of 8 consecutive semiprimes.
%C A217222 Note that in all cases "9th term" (in this case 8143+2=8145) is divisible by 9 and hence is not semiprime.
%C A217222 Also note that all seven "intermediate" even integers (in this case {8130, 8132, 8134, 8136, 8138, 8140, 8142}) have at least three prime factors counting with multiplicity. Up to n = 40*10^9 there are 5570 terms of this sequence.
%H A217222 Zak Seidov, <a href="/A217222/b217222.txt">Table of n, a(n) for n = 1..5570</a>
%t A217222 Transpose[Select[Partition[Select[Range[26*10^6],PrimeOmega[#] == 2&],8,1], Union[ Differences[#]]=={2}&]][[1]] (* _Harvey P. Dale_, Sep 02 2015 *)
%Y A217222 Subsequence of A082919.
%Y A217222 Cf. A056809, A070552, A092125-A092129, A092207-A092209.
%K A217222 nonn
%O A217222 1,1
%A A217222 _Zak Seidov_, Sep 28 2012