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 A214428 #17 Feb 16 2025 08:33:18 %S A214428 561,1105,2465,278545,3224065,11119105,2479305985,123155771490305 %N A214428 Carmichael numbers n such that A002322(n) = 2^k * p, where k is an integer and p is a prime. %C A214428 Wright (2012) proves that given the 5 known Fermat primes (A019434), these are the only numbers possible. %H A214428 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CarmichaelFunction.html">Carmichael Function</a>. %H A214428 Thomas Wright, <a href="http://www.emis.de/journals/INTEGERS/papers/m31/m31.Abstract.html">The impossibility of certain types of Carmichael numbers</a>, INTEGERS 12 (2012), A31. %Y A214428 Cf. A002997 (Carmichael numbers), A002322, A019434, A293291. %K A214428 nonn,hard %O A214428 1,1 %A A214428 _T. D. Noe_, Jul 19 2012