447944domain: NAppears in sequencesa(n) is the number of terms in the expansion of (x+y-z)*(x^2+y^2-z^2)*(x^3+y^3-z^3)*...*(x^n+y^n-z^n).at n=42A086817Expansion of 1/(1 - x - x^2 - x^3 + x^6 + x^7).at n=23A260917