Number of length-(n+1) 0..3 arrays with new values introduced in sequential order, and with new repeated values introduced in sequential order, both starting with zero.
A268322
Number of length-(n+1) 0..3 arrays with new values introduced in sequential order, and with new repeated values introduced in sequential order, both starting with zero.
Terms
- a(0) =2a(1) =4a(2) =11a(3) =32a(4) =102a(5) =337a(6) =1148a(7) =3984a(8) =14030a(9) =49973a(10) =179735a(11) =652010a(12) =2383857a(13) =8779485a(14) =32555471a(15) =121497802a(16) =456178652a(17) =1722502343a(18) =6538543106a(19) =24942393310a(20) =95581407132a(21) =367817900179
External references
- oeis: A268322