Number of compositions of 6*n into parts 1 and 6.

Terms

a(0) =1a(1) =2a(2) =9a(3) =43a(4) =196a(5) =882a(6) =3970a(7) =17887a(8) =80608a(9) =363254a(10) =1636944a(11) =7376591a(12) =33241289a(13) =149795989a(14) =675029164a(15) =3041899638a(16) =13707783053a(17) =61771701389a(18) =278363253873