How do we calculate

**the weight** for a form (k*b^n+c)/gcd(k+c,b-1) for fixed integers k >= 1, b >= 2, c != 0, gcd(k,c) = 1, gcd(b,c) = 1.

I have a

research that whether the form (k*b^n+c)/gcd(k+c,b-1) can contain a prime (there are special cases, such as (27*8^n+1)/7, (1*8^n-1)/7, (1*16^n-1)/15, and (4*16^n+1)/5, they can contain

**only one** prime (because of the algebra factors), thus the weight is also 0, besides, there are also cases without covering set or algebra factors, but cannot contain a prime, such as 8*128^n+1 and 32*128^n+1)

(I know that the

dual forms have the same weight)