OFFSET
1,1
COMMENTS
The first term that has more than 2 prime factors is a(1067) = A333131(1) = 11500521553.
The first term that is also a Carmichael number is a(1131) = 13079177569.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
2701 is a term since it is a Fermat pseudoprime to both bases 2 and 3, and its proper divisors that are larger than 1 are all primes: 37 and 73.
MATHEMATICA
pspQ[n_] := CompositeQ[n] && AllTrue[Rest @ Divisors[n], PowerMod[2, # - 1, #] == 1 && PowerMod[3, # - 1, #] == 1 &]; Select[Range[10^6], pspQ]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Mar 08 2020
STATUS
approved