Number of compositions of n with at most one 1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =4a(5) =8a(6) =13a(7) =23a(8) =39a(9) =67a(10) =114a(11) =194a(12) =329a(13) =557a(14) =941a(15) =1587a(16) =2672a(17) =4492a(18) =7541a(19) =12643a(20) =21171a(21) =35411a(22) =59166a(23) =98758a(24) =164689a(25) =274393a(26) =456793a(27) =759843a(28) =1263004a(29) =2097872