Number of compositions of 6*n-4 into parts 1 and 6.

Terms

a(0) =1a(1) =4a(2) =16a(3) =71a(4) =322a(5) =1455a(6) =6558a(7) =29548a(8) =133146a(9) =599998a(10) =2703794a(11) =12184181a(12) =54905857a(13) =247423522a(14) =1114970351a(15) =5024416818a(16) =22641646338a(17) =102030577247a(18) =459782762029