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 A194946 #18 Jul 10 2015 23:27:38 %S A194946 9,15,45,65,91,231,325,341,481,703,1541,1891,2701,5461,6533,8321, %T A194946 11041,12403,18721,30889,38503,49141,68101,79003,88561,88831,104653, %U A194946 137149,146611,176149,188191,218791,226801,269011,286903,385003,493697,497503,563473 %N A194946 Odd non-Carmichael numbers with increasing numbers of bases to which they are pseudoprimes. %C A194946 A141768 is the analog using the Rabin-Miller test rather than the Fermat test. The infinitude of that sequence implies that this sequence is likewise infinite. %H A194946 Charles R Greathouse IV, <a href="/A194946/b194946.txt">Table of n, a(n) for n = 1..659</a> %H A194946 <a href="/index/Ps#pseudoprimes">Index entries for sequences related to pseudoprimes</a> %o A194946 (PARI) bases(n)=my(f=factor(n)[,1]);n--;prod(i=1,#f,gcd(f[i]-1,n)) %o A194946 Korselt(n)=my(f=factor(n));for(i=1,#f[,1],if(f[i,2]>1||(n-1)%(f[i,1]-1),return(0)));1 %o A194946 r=0;p=5;forprime(q=7,1e7,forstep(n=p+2,q-2,2,if(bases(n)>r&&!Korselt(n), r=bases(n);print1(n", ")));p=q) \\ _Charles R Greathouse IV_, Sep 14 2011 %Y A194946 Cf. A195327 (number of bases). %Y A194946 Cf. A141768. %K A194946 nonn %O A194946 1,1 %A A194946 _Charles R Greathouse IV_, Sep 13 2011