[seqfan] A180248

[Klaus Brockhaus]

There are 72 terms < 300000; they include the first 25 Carmichael 
numbers (A002997):

15,91,435,561,703,1105,1729,1891,2465,2701,2821,3367,5551,6601,8695,
8911,10585,11305,12403,13981,15051,15841,16471,18721,23001,26335,29341,
30889,38503,39865,41041,46657,49141,52633,53131,62745,63973,68101,
75361,76627,79003,88561,88831,91001,93961,101101,101935,104653,107185,
115921,126217,137149,139231,146611,152551,157641,162401,172081,176149,
188191,188461,204001,218791,226801,228241,251251,252601,269011,276013,
278545,286903,294409,

I computed also the corresponding S-values. This gives further numerical 
support to the conjecture,
that n is a Carmichael number if and only if n is a term of A180248 and 
all S-values of n are even.

KB