Number of n-color gap-free compositions of n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =7a(5) =19a(6) =45a(7) =105a(8) =239a(9) =507a(10) =1079a(11) =2303a(12) =4829a(13) =10425a(14) =23263a(15) =53363a(16) =127995a(17) =318983a(18) =816057a(19) =2133241a(20) =5640135a(21) =14975051a(22) =39772751a(23) =105322879a(24) =277547989a(25) =727276225a(26) =1894282195a(27) =4903985955a(28) =12621154315a(29) =32302574959