Number of compositions of n with exactly two occurrences of the largest part.

Terms

a(0) =1a(1) =0a(2) =1a(3) =3a(4) =7a(5) =13a(6) =25a(7) =46a(8) =89a(9) =175a(10) =351a(11) =710a(12) =1443a(13) =2926a(14) =5920a(15) =11936a(16) =23987a(17) =48072a(18) =96139a(19) =191977a(20) =382992a(21) =763686a(22) =1522581a(23) =3035979a(24) =6055454a(25) =12082887a(26) =24120923a(27) =48174935a(28) =96259627a(29) =192418152