Number of compositions of 5*n-3 into parts 1 and 5.

Terms

a(0) =1a(1) =4a(2) =15a(3) =60a(4) =245a(5) =1001a(6) =4085a(7) =16665a(8) =67985a(9) =277350a(10) =1131476a(11) =4615966a(12) =18831276a(13) =76823991a(14) =313410816a(15) =1278589392a(16) =5216127688a(17) =21279691689a(18) =86812537085a(19) =354160046356