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 A046419 #24 Feb 16 2025 08:32:39 %S A046419 28,51,55,58,77,86,95,98,107,115,119,124,155,161,193,209,217,218,221, %T A046419 233,253,265,295,298,303,314,346 %N A046419 Repunit of length a(n) has exactly 8 prime factors (counted with multiplicity). %H A046419 P. De Geest, <a href="https://www.worldofnumbers.com/repunits.htm">Repunits prime factors</a> %H A046419 Makoto Kamada, <a href="https://stdkmd.net/nrr/repunit/">Factorizations of 11...11 (Repunit)</a> %H A046419 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Repunit.html">Repunit</a> %t A046419 Select[Range[320],PrimeOmega[FromDigits[Table[1,#]]]==8&] (* _Harvey P. Dale_, Sep 04 2018 *) %Y A046419 Cf. A000042, A001222, A002275, A004022, A004023, A046053. %K A046419 nonn,base,more %O A046419 1,1 %A A046419 _Patrick De Geest_, Jul 15 1998 %E A046419 More terms from _Robert Gerbicz_, Nov 22 2010 %E A046419 Offset changed to 1, a(23)-a(26) added by _Ray Chandler_, Apr 23 2017 %E A046419 a(27) from _Max Alekseyev_, May 14 2022