a(n) = 5a(n-1) - 5a(n-2) + a(n-3) + 2*(-1)^(n+1), alternatively a(n) = 3a(n-1) + 3a(n-2) - a(n-3).
A109438
a(n) = 5a(n-1) - 5a(n-2) + a(n-3) + 2*(-1)^(n+1), alternatively a(n) = 3a(n-1) + 3a(n-2) - a(n-3).
Terms
- a(0) =1a(1) =5a(2) =18a(3) =68a(4) =253a(5) =945a(6) =3526a(7) =13160a(8) =49113a(9) =183293a(10) =684058a(11) =2552940a(12) =9527701a(13) =35557865a(14) =132703758a(15) =495257168a(16) =1848324913a(17) =6898042485a(18) =25743845026a(19) =96077337620a(20) =358565505453
External references
- oeis: A109438