a(1)=1, a(n) = ceiling(r(3)*a(n-1)) where r(3) = (1/2)*(3 + sqrt(13)) is the positive root of X^2 = 3*X + 1.

A082574

a(1)=1, a(n) = ceiling(r(3)*a(n-1)) where r(3) = (1/2)*(3 + sqrt(13)) is the positive root of X^2 = 3*X + 1.

Terms

    a(0) =1a(1) =4a(2) =14a(3) =47a(4) =156a(5) =516a(6) =1705a(7) =5632a(8) =18602a(9) =61439a(10) =202920a(11) =670200a(12) =2213521a(13) =7310764a(14) =24145814a(15) =79748207a(16) =263390436a(17) =869919516a(18) =2873148985a(19) =9489366472a(20) =31341248402a(21) =103513111679a(22) =341880583440

External references