69923042domain: NAppears in sequencesExpansion of (1-x-x^2+2*x^3) / ((1-x)*(1+x)*(1-3*x+x^2)).at n=19A038990a(n) = F(n)^2 + F(n+1)^2 + F(n+2)^2, where F(n) denotes the n-th Fibonacci number.at n=18A127546a(n) = A000045(n)*A000045(n+1) mod A000032(n).at n=38A357553