a(n) = (2*F(3*n) - F(n))/3, where F=A000045 (the Fibonacci sequence).

A049675

a(n) = (2*F(3*n) - F(n))/3, where F=A000045 (the Fibonacci sequence).

Terms

    a(0) =0a(1) =1a(2) =5a(3) =22a(4) =95a(5) =405a(6) =1720a(7) =7293a(8) =30905a(9) =130934a(10) =554675a(11) =2349689a(12) =9953520a(13) =42163913a(14) =178609405a(15) =756601910a(16) =3205017655a(17) =13576673517a(18) =57511713320a(19) =243623529381

External references