Number of compositions of 6*n-3 into parts 1 and 6.

Terms

a(0) =1a(1) =5a(2) =21a(3) =92a(4) =414a(5) =1869a(6) =8427a(7) =37975a(8) =171121a(9) =771119a(10) =3474913a(11) =15659094a(12) =70564951a(13) =317988473a(14) =1432958824a(15) =6457375642a(16) =29099021980a(17) =131129599227a(18) =590912361256