Number of compositions of n with first part 4 and no equal adjacent parts; this is column 4 of the array in A096568.
A096572
Number of compositions of n with first part 4 and no equal adjacent parts; this is column 4 of the array in A096568.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =3a(7) =3a(8) =6a(9) =13a(10) =20a(11) =36a(12) =65a(13) =111a(14) =194a(15) =342a(16) =596a(17) =1041a(18) =1830a(19) =3200a(20) =5593a(21) =9802a(22) =17148a(23) =30002a(24) =52537a(25) =91940a(26) =160897a(27) =281646a(28) =492933a(29) =862718
External references
- oeis: A096572