Code:

1,0
2,2
3,1
4,1
5,4
6,1
7,1
8,8
9,(partial algebra factors)
10,6783
11,4
12,8
13,1
14,4
15,2
16,3

With CK=17

All k where k = m^2 and m = = 3 or 5 mod 8:

for even n let k = m^2 and let n = 2*q; factors to:

(m*185^q - 1) * (m*185^q + 1)

odd n:

factor of 2

This includes k = 9

k=10 prime given by

CRUS
k = 1 remain at n=66337, see post

https://mersenneforum.org/showpost.p...&postcount=225