5242881domain: NAppears in sequencesa(0) = 6; for n>0, a(n) = 2*a(n-1) - 1.at n=20A083575A007318 * A131055.at n=19A131056a(n) = 5*4^n+1.at n=10A199115Expansion of Sum_{k>0} (x * (1 + (2 * x)^k))^k.at n=24A360752