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 A106125 #31 Oct 16 2022 03:24:31 %S A106125 1,2,3,7,11,43,53,613367,613439,613451,613523,613549,613609, %T A106125 6384425461,6384425521,6384425569,6384425647 %N A106125 Numbers k such that k divides the k-th semiprime. %C A106125 Note that except 1, all other term in the sequence will be primes. %C A106125 a(18) > 10^12. - _Lucas A. Brown_, Oct 17 2020 %H A106125 Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/semiprimemods.py">semiprimemods.py</a> %e A106125 a(4)=7 is a term because 7 divides the 7th semiprime (i.e., 21). %Y A106125 Cf. A001358, A356764, A357741. %K A106125 nonn,hard,more %O A106125 1,2 %A A106125 _Shyam Sunder Gupta_, May 07 2005 %E A106125 a(14)-a(17) from _Donovan Johnson_, Sep 27 2010