Number of length n+2 0..9 arrays with no three unequal elements in a row and new values 0..9 introduced in 0..9 order.
A243640
Number of length n+2 0..9 arrays with no three unequal elements in a row and new values 0..9 introduced in 0..9 order.
Terms
- a(0) =4a(1) =9a(2) =21a(3) =51a(4) =127a(5) =324a(6) =844a(7) =2243a(8) =6073a(9) =16737a(10) =46905a(11) =133556a(12) =386062a(13) =1132107a(14) =3365627a(15) =10137559a(16) =30920943a(17) =95457177a(18) =298128257a(19) =941574130a(20) =3006037464a(21) =9697650031a(22) =31602766791a(23) =104000078093a(24) =345512414521
External references
- oeis: A243640