Number of compositions of n with first part 2 and no equal adjacent parts; this is column 2 of the array in A096568.
A096570
Number of compositions of n with first part 2 and no equal adjacent parts; this is column 2 of the array in A096568.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =0a(4) =2a(5) =4a(6) =5a(7) =10a(8) =18a(9) =29a(10) =53a(11) =95a(12) =161a(13) =283a(14) =500a(15) =869a(16) =1524a(17) =2673a(18) =4665a(19) =8170a(20) =14313a(21) =25032a(22) =43817a(23) =76710a(24) =134228a(25) =234938a(26) =411242a(27) =719720a(28) =1259677a(29) =2204816
External references
- oeis: A096570