Number of integer compositions of n that are the first sums of more than one nonnegative sequence.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =13a(5) =22a(6) =39a(7) =65a(8) =112a(9) =185a(10) =313a(11) =514a(12) =859a(13) =1405a(14) =2328a(15) =3797a(16) =6253a(17) =10178a(18) =16687a(19) =27121a(20) =44320a(21) =71953a(22) =117297a(23) =190274a(24) =309619a(25) =501941a(26) =815656a(27) =1321693a(28) =2145541a(29) =3475426