Number of compositions of 5*n into parts 2 and 5.

Terms

a(0) =1a(1) =1a(2) =2a(3) =7a(4) =23a(5) =68a(6) =194a(7) =555a(8) =1601a(9) =4633a(10) =13404a(11) =38752a(12) =112004a(13) =323728a(14) =935737a(15) =2704817a(16) =7818464a(17) =22599701a(18) =65325542a(19) =188826693a(20) =545813094a(21) =1577700612a(22) =4560424135a(23) =13182138184a(24) =38103641048a(25) =110140512968a(26) =318366757185a(27) =920255312908