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 A114249 #22 Feb 16 2025 08:32:59
%S A114249 1,2,6,16,73,234,659,1797,4950,13070,33989,87448
%N A114249 Number of Fermat pseudoprimes to base 7 less than 10^n.
%H A114249 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/FermatPseudoprime.html">Fermat Pseudoprime</a>
%t A114249 Table[Count[Select[Range[2, 10^6], ! PrimeQ[#] && PowerMod[7, # - 1, #] == 1 &], x_ /; x < 10^n], {n, 6}] (* _Robert Price_, Jun 09 2019 *)
%Y A114249 Cf. A005938, A055550, A114245, A114247.
%K A114249 nonn,more
%O A114249 1,2
%A A114249 _Eric W. Weisstein_, Nov 18 2005
%E A114249 a(9)-a(12) from _Hiroaki Yamanouchi_, Sep 25 2015