Number of Carlitz compositions of n with exactly three descents.

Terms

a(0) =3a(1) =11a(2) =31a(3) =78a(4) =175a(5) =363a(6) =715a(7) =1342a(8) =2421a(9) =4237a(10) =7208a(11) =11971a(12) =19473a(13) =31083a(14) =48787a(15) =75437a(16) =115046a(17) =173263a(18) =257972a(19) =380039a(20) =554400a(21) =801452a(22) =1148805a(23) =1633699a(24) =2306108a(25) =3232635a(26) =4501745a(27) =6230400a(28) =8572442a(29) =11729536