26589395581domain: NAppears in sequencesSum(C(j)*(n-j)*4^(n-j-1),j=0..n-1), C = Catalan numbers.at n=16A018218a(n) = 2^(2*n - HammingWeight(n)) * [x^n] ((x - 1)^(-2) - (1 - x)^(-3/2)).at n=16A380952