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 A091022 #18 Feb 21 2025 18:09:10
%S A091022 10,15,25,26,38,39,58,62,74,77,94,95,106,118,119,141,145,155,166,177,
%T A091022 178,194,203,213,219,235,254,265,267,274,291,298,299,301,329,346,362,
%U A091022 377,381,386,391,393,411,422,427,454,458,466,471,473,502,514,515,519
%N A091022 Semiprimes with semiprime indices.
%C A091022 Semiprime of semiprime of n: a(n) = A001358(A001358(n)). - _Jonathan Vos Post_, Apr 29 2005
%e A091022 10 is a member because 10 is 4th semiprime and 4 is a semiprime.
%t A091022 With[{sprs=Select[Range[700],PrimeOmega[#]==2&]},Flatten[Table[Take[sprs, Take[ sprs,{n}]],{n,60}]]] (* _Harvey P. Dale_, Aug 22 2011 *)
%o A091022 (PARI) upto(limit)={ my(spr=select(x->bigomega(x)==2,[1..limit]), n=1); while(spr[n]<#spr, n++); vecextract(spr,spr[1..n]) } \\ _R. J. Mathar_, May 23 2006
%Y A091022 Cf. A001358, A007097.
%K A091022 nonn
%O A091022 1,1
%A A091022 _Zak Seidov_, Feb 24 2004