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 A174617 #25 Apr 22 2025 10:49:08 %S A174617 0,0,0,0,0,0,0,0,0,0,0,0,0,1,27,170,1436,8835,44993,196391,762963, %T A174617 2714473,8939435 %N A174617 Number of nine-prime Carmichael numbers less than 10^n. %D A174617 Paulo Ribenboim, The Little Book of Bigger Primes, Springer-Verlag NY 2004. See p. 220. %H A174617 Claude Goutier, <a href="http://www-labs.iro.umontreal.ca/~goutier/OEIS/A055553/">Text file readme.text summarizing enumeration of Carmichael numbers up to 10^22</a>. %H A174617 Claude Goutier, <a href="/A055553/a055553.txt">Text file readme.text summarizing enumeration of Carmichael numbers up to 10^22</a>. [Local copy, with permission] %H A174617 R. G. E. Pinch, <a href="http://s369624816.websitehome.co.uk/rgep/p82.pdf">The Carmichael numbers up to 10^21</a>, Proceedings of Conference on Algorithmic Number Theory 2007. %H A174617 R. G. E. Pinch, <a href="http://s369624816.websitehome.co.uk/rgep/p82p.pdf">The Carmichael numbers up to 10^21</a>, Poster, Proceedings of Conference on Algorithmic Number Theory 2007. %e A174617 The smallest Carmichael number with 9 prime factors is 9746347772161 = 7*11*13*17*19*31*37*41*641, so a(13)=1.. %Y A174617 For k-prime Carmichael numbers up to 10^n for k = 3,4,...,11, see A132195, A174612, A174613, A174614, A174615, A174616, A174617, A299710, A299711. %Y A174617 Cf. A002997, A006931, A055553. %K A174617 nonn,more %O A174617 0,15 %A A174617 _Michel Lagneau_, Mar 23 2010 %E A174617 a(22) from _Claude Goutier_ added by _Amiram Eldar_, Apr 19 2024