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 A102205 #14 Jul 22 2025 19:32:49
%S A102205 4,5071,6313,31591,9853,11733,31865,736481,9834802,5123383,906334841,
%T A102205 312395329,73044385753,39216355244851,353123779923181,944016528715333,
%U A102205 901870160743125919,3394064622591216338731,798539095539570459224764519,5844680137439021618014007903
%N A102205 Iccanobirt semiprimes (15 of 15): Semiprime numbers in A102125.
%F A102205 a(n) = A102125(A102185(n)).
%t A102205 nxt[{a_,b_,c_}]:=With[{ir=IntegerReverse},{b,c,ir[ir[a]+ir[b]+ir[c]]}]; Select[NestList[nxt,{0,0,1},200][[;;,1]],PrimeOmega[#]==2&] (* _Harvey P. Dale_, Jul 22 2025 *)
%Y A102205 Cf. A001358, A102125, A102185, A102191-A102204.
%K A102205 nonn,less,base
%O A102205 1,1
%A A102205 _Jonathan Vos Post_ and _Ray Chandler_, Dec 31 2004
%E A102205 Offset changed to 1 and a(20) from _Jinyuan Wang_, Aug 14 2021