Number of quinternary strings avoiding consecutive digits i,i+1 and i,i+2.
A284840
Number of quinternary strings avoiding consecutive digits i,i+1 and i,i+2.
Terms
- a(0) =1a(1) =5a(2) =18a(3) =63a(4) =224a(5) =799a(6) =2846a(7) =10132a(8) =36073a(9) =128438a(10) =457304a(11) =1628224a(12) =5797263a(13) =20641062a(14) =73492179a(15) =261667749a(16) =931663897a(17) =3317174627a(18) =11810748015a(19) =42051982296a(20) =149725420655a(21) =533095002085
External references
- oeis: A284840