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 A106126 #30 Oct 13 2022 12:48:07 %S A106126 1,27,28,35,40,44,47,55,56,72,613400,613401,613457,613482,613530, %T A106126 613538,613544,613550,613554,613556,613560,613614,58155520,58155521, %U A106126 58155533,58155537,58155540,58155543,58155545,58155571,6384425460,6384425506,6384425524 %N A106126 Numbers k such that k-th semiprime == 1 (mod k). %C A106126 a(45) > 10^12. - _Lucas A. Brown_, Oct 17 2020 %H A106126 Lucas A. Brown, <a href="/A106126/b106126.txt">Table of n, a(n) for n = 1..44</a> %H A106126 Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/semiprimemods.py">semiprimemods.py</a> %e A106126 27 is a term because the 27th semiprime (i.e., 82) == 1 (mod 27). %Y A106126 Cf. A001358, A357781. %K A106126 hard,nonn %O A106126 1,2 %A A106126 _Shyam Sunder Gupta_, May 07 2005 %E A106126 a(23)-a(30) from _Donovan Johnson_, Oct 29 2008 %E A106126 a(1) and a(31)-a(33) from _Lucas A. Brown_, Oct 17 2020