a(n) = (Sum_{j=1..h-1} a(n-j) + a(n-1)*a(n-h+1))/a(n-h) with a(1), ..., a(h)=1, where h = 6.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =6a(7) =16a(8) =41a(9) =106a(10) =276a(11) =2101a(12) =6026a(13) =15976a(14) =41901a(15) =109726a(16) =835906a(17) =2397991a(18) =6358066a(19) =16676206a(20) =43670551a(21) =332688201a(22) =954394051a(23) =2530493951a(24) =6637087801a(25) =17380769451a(26) =132409067806a(27) =379846433966