Number of compositions of n into parts of sizes == 1 mod 5 or 4 mod 5.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =5a(6) =7a(7) =10a(8) =15a(9) =23a(10) =35a(11) =52a(12) =77a(13) =115a(14) =173a(15) =260a(16) =389a(17) =581a(18) =869a(19) =1302a(20) =1951a(21) =2921a(22) =4371a(23) =6542a(24) =9795a(25) =14667a(26) =21959a(27) =32872a(28) =49209a(29) =73671