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 A046418 #23 Feb 16 2025 08:32:39
%S A046418 12,20,21,22,27,35,61,65,74,82,85,141,146,177,187,194,226,299,323,329,
%T A046418 337
%N A046418 Repunit of length a(n) has exactly 7 prime factors (counted with multiplicity).
%H A046418 P. De Geest, <a href="https://www.worldofnumbers.com/repunits.htm">Repunits prime factors</a>
%H A046418 Makoto Kamada, <a href="https://stdkmd.net/nrr/repunit/">Factorizations of 11...11 (Repunit)</a>
%H A046418 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Repunit.html">Repunit</a>
%t A046418 Select[Range[300],PrimeOmega[FromDigits[PadRight[{},#,1]]]==7&] (* _Harvey P. Dale_, Feb 04 2019 *)
%Y A046418 Cf. A000042, A001222, A002275, A004022, A004023, A046053.
%K A046418 nonn,base,more
%O A046418 1,1
%A A046418 _Patrick De Geest_, Jul 15 1998
%E A046418 More terms from _Robert Gerbicz_, Nov 22 2010
%E A046418 Changed offset to 1, a(18) added by _Ray Chandler_, Apr 23 2017
%E A046418 a(19)-a(21) from _Max Alekseyev_, May 14 2022